diff --git a/.github/workflows/cuda.yml b/.github/workflows/cuda.yml
deleted file mode 100644
index 4b47d9bef65a..000000000000
--- a/.github/workflows/cuda.yml
+++ /dev/null
@@ -1,96 +0,0 @@
-name: CUDA Version
-
-on:
-  push:
-    branches:
-    - master
-  pull_request:
-    branches:
-    - master
-
-env:
-  github_actions: 'true'
-  os_name: linux
-  task: cuda
-  conda_env: test-env
-
-jobs:
-  test:
-    name: cuda ${{ matrix.cuda_version }} ${{ matrix.method }} (linux, ${{ matrix.compiler }}, Python ${{ matrix.python_version }})
-    runs-on: [self-hosted, linux]
-    timeout-minutes: 60
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - method: source
-            compiler: gcc
-            python_version: 3.7
-            cuda_version: "11.2.0"
-          - method: pip
-            compiler: clang
-            python_version: 3.8
-            cuda_version: "10.0"
-          - method: wheel
-            compiler: gcc
-            python_version: 3.9
-            cuda_version: "9.0"
-    steps:
-      - name: Setup or update software on host machine
-        run: |
-            sudo apt-get update
-            sudo apt-get install --no-install-recommends -y \
-                apt-transport-https \
-                ca-certificates \
-                curl \
-                git \
-                gnupg-agent \
-                software-properties-common
-            curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
-            sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" -y
-            curl -sL https://nvidia.github.io/nvidia-docker/gpgkey | sudo apt-key add -
-            curl -sL https://nvidia.github.io/nvidia-docker/$(. /etc/os-release;echo $ID$VERSION_ID)/nvidia-docker.list | sudo tee /etc/apt/sources.list.d/nvidia-docker.list
-            sudo apt-get update
-            sudo apt-get install --no-install-recommends -y \
-                containerd.io \
-                docker-ce \
-                docker-ce-cli \
-                nvidia-docker2
-            sudo chmod a+rw /var/run/docker.sock
-            sudo systemctl restart docker
-      - name: Remove old folder with repository
-        run: sudo rm -rf $GITHUB_WORKSPACE
-      - name: Checkout repository
-        uses: actions/checkout@v1
-        with:
-          fetch-depth: 5
-          submodules: true
-      - name: Setup and run tests
-        run: |
-            export ROOT_DOCKER_FOLDER=/LightGBM
-            cat > docker.env <<EOF
-            GITHUB_ACTIONS=${{ env.github_actions }}
-            OS_NAME=${{ env.os_name }}
-            COMPILER=${{ matrix.compiler }}
-            TASK=${{ env.task }}
-            METHOD=${{ matrix.method }}
-            CONDA_ENV=${{ env.conda_env }}
-            PYTHON_VERSION=${{ matrix.python_version }}
-            BUILD_DIRECTORY=$ROOT_DOCKER_FOLDER
-            LGB_VER=$(head -n 1 VERSION.txt)
-            EOF
-            cat > docker-script.sh <<EOF
-            export CONDA=\$HOME/miniconda
-            export PATH=\$CONDA/bin:\$PATH
-            nvidia-smi
-            $ROOT_DOCKER_FOLDER/.ci/setup.sh || exit -1
-            $ROOT_DOCKER_FOLDER/.ci/test.sh || exit -1
-            EOF
-            docker run --env-file docker.env -v "$GITHUB_WORKSPACE":"$ROOT_DOCKER_FOLDER" --rm --gpus all "nvidia/cuda:${{ matrix.cuda_version }}-devel" /bin/bash $ROOT_DOCKER_FOLDER/docker-script.sh
-  all-successful:
-    # https://github.community/t/is-it-possible-to-require-all-github-actions-tasks-to-pass-without-enumerating-them/117957/4?u=graingert
-    runs-on: ubuntu-latest
-    needs: [test]
-    steps:
-    - name: Note that all tests succeeded
-      run: echo "🎉"
diff --git a/.github/workflows/linkchecker.yml b/.github/workflows/linkchecker.yml
deleted file mode 100644
index 13fd3303e54f..000000000000
--- a/.github/workflows/linkchecker.yml
+++ /dev/null
@@ -1,33 +0,0 @@
-name: Link checks
-
-on:
-  # Run manually by clicking a button in the UI
-  workflow_dispatch:
-  # Run once a day at 8:00am UTC
-  schedule:
-    - cron: '0 8 * * *'
-
-env:
-  CONDA_ENV: test-env
-  GITHUB_ACTIONS: 'true'
-  OS_NAME: 'linux'
-  PYTHON_VERSION: 3.9
-  TASK: 'check-links'
-
-jobs:
-  check-links:
-    timeout-minutes: 60
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v2.3.4
-        with:
-          fetch-depth: 5
-          submodules: false
-      - name: Setup and run tests
-        run: |
-          export BUILD_DIRECTORY="$GITHUB_WORKSPACE"
-          export CONDA=${HOME}/miniconda
-          export PATH=${CONDA}/bin:${HOME}/.local/bin:${PATH}
-          $GITHUB_WORKSPACE/.ci/setup.sh || exit -1
-          $GITHUB_WORKSPACE/.ci/test.sh || exit -1
diff --git a/.github/workflows/optional_checks.yml b/.github/workflows/optional_checks.yml
deleted file mode 100644
index 9b679986f6ec..000000000000
--- a/.github/workflows/optional_checks.yml
+++ /dev/null
@@ -1,30 +0,0 @@
-name: Optional checks
-
-on:
-  pull_request:
-    branches:
-      - master
-
-jobs:
-  all-successful:
-    timeout-minutes: 120
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v2.3.4
-        with:
-          fetch-depth: 5
-          submodules: false
-      - name: Check that all tests succeeded
-        run: |
-            workflows=(
-                "R valgrind tests;r-valgrind"
-                "Solaris CRAN check;r-solaris"
-            )
-            for i in "${workflows[@]}"; do
-                workflow_name=${i%;*}
-                trigger_phrase=${i#*;}
-                python "$GITHUB_WORKSPACE/.ci/get_workflow_status.py" "$trigger_phrase" \
-                || { echo "The last reported status from workflow \"$workflow_name\" is failure. Commit fixes and rerun the workflow."; \
-                exit -1; }
-            done
diff --git a/.github/workflows/python_package.yml b/.github/workflows/python_package.yml
deleted file mode 100644
index 22a9b58ef993..000000000000
--- a/.github/workflows/python_package.yml
+++ /dev/null
@@ -1,79 +0,0 @@
-name: Python-package
-
-on:
-  push:
-    branches:
-    - master
-  pull_request:
-    branches:
-    - master
-
-env:
-  CONDA_ENV: test-env
-  GITHUB_ACTIONS: 'true'
-
-jobs:
-  test:
-    name: ${{ matrix.task }} ${{ matrix.method }} (${{ matrix.os }}, Python ${{ matrix.python_version }})
-    runs-on: ${{ matrix.os }}
-    timeout-minutes: 60
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - os: macOS-latest
-            task: regular
-            python_version: 3.6
-          - os: macOS-latest
-            task: sdist
-            python_version: 3.9
-          - os: macOS-latest
-            task: bdist
-            python_version: 3.8
-          - os: macOS-latest
-            task: if-else
-            python_version: 3.8
-          - os: macOS-latest
-            task: mpi
-            method: source
-            python_version: 3.9
-          - os: macOS-latest
-            task: mpi
-            method: pip
-            python_version: 3.6
-          - os: macOS-latest
-            task: mpi
-            method: wheel
-            python_version: 3.7
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v2.3.4
-        with:
-          fetch-depth: 5
-          submodules: true
-      - name: Setup and run tests
-        shell: bash
-        run: |
-          export TASK="${{ matrix.task }}"
-          export METHOD="${{ matrix.method }}"
-          export PYTHON_VERSION="${{ matrix.python_version }}"
-          if [[ "${{ matrix.os }}" == "macOS-latest" ]]; then
-              export COMPILER="gcc"
-              export OS_NAME="macos"
-          elif [[ "${{ matrix.os }}" == "ubuntu-latest" ]]; then
-              export COMPILER="clang"
-              export OS_NAME="linux"
-          fi
-          export BUILD_DIRECTORY="$GITHUB_WORKSPACE"
-          export LGB_VER=$(head -n 1 VERSION.txt)
-          export CONDA=${HOME}/miniconda
-          export PATH=${CONDA}/bin:${PATH}
-          $GITHUB_WORKSPACE/.ci/setup.sh || exit -1
-          $GITHUB_WORKSPACE/.ci/test.sh || exit -1
-  all-successful:
-    # https://github.community/t/is-it-possible-to-require-all-github-actions-tasks-to-pass-without-enumerating-them/117957/4?u=graingert
-    runs-on: ubuntu-latest
-    needs: [test]
-    steps:
-    - name: Note that all tests succeeded
-      run: echo "🎉"
diff --git a/.github/workflows/r_artifacts.yml b/.github/workflows/r_artifacts.yml
deleted file mode 100644
index d69a1f4d2656..000000000000
--- a/.github/workflows/r_artifacts.yml
+++ /dev/null
@@ -1,57 +0,0 @@
-name: R artifact builds
-
-on:
-  repository_dispatch:
-    types: [gha_run_build_r_artifacts]
-
-jobs:
-  cran-package:
-    name: cran-package
-    timeout-minutes: 60
-    runs-on: ubuntu-latest
-    container: rocker/r-base
-    env:
-      SECRETS_WORKFLOW: ${{ secrets.WORKFLOW }}
-    steps:
-      - name: Install essential software before checkout
-        shell: bash
-        run: |
-          apt-get update
-          apt-get install --no-install-recommends -y \
-            curl \
-            git \
-            jq
-      - name: Checkout repository
-        uses: actions/checkout@v2.3.4
-        with:
-          fetch-depth: 5
-          submodules: true
-          repository: microsoft/LightGBM
-          ref: "refs/pull/${{ github.event.client_payload.pr_number }}/merge"
-      - name: Send init status
-        if: ${{ always() }}
-        run: |
-          $GITHUB_WORKSPACE/.ci/append_comment.sh \
-            "${{ github.event.client_payload.comment_number }}" \
-            "Workflow **${{ github.workflow }}** has been triggered! 🚀\r\n${GITHUB_SERVER_URL}/microsoft/LightGBM/actions/runs/${GITHUB_RUN_ID}"
-      - name: Build package
-        shell: bash
-        id: build_package
-        run: |
-          sh build-cran-package.sh || exit -1
-          LGB_VERSION=$(cat VERSION.txt | sed "s/rc/-/g")
-          ARTIFACT_NAME=lightgbm-${LGB_VERSION}-r-cran.tar.gz
-          mv lightgbm_${LGB_VERSION}.tar.gz ${ARTIFACT_NAME}
-          echo "::set-output name=artifact_name::${ARTIFACT_NAME}"
-          echo "::set-output name=artifact_path::$(pwd)/${ARTIFACT_NAME}"
-      - name: Upload package
-        uses: actions/upload-artifact@v2
-        with:
-          name: ${{ steps.build_package.outputs.artifact_name }}
-          path: ${{ steps.build_package.outputs.artifact_path }}
-      - name: Send final status
-        if: ${{ always() }}
-        run: |
-          $GITHUB_WORKSPACE/.ci/append_comment.sh \
-            "${{ github.event.client_payload.comment_number }}" \
-            "Status: ${{ job.status }}."
diff --git a/.github/workflows/r_package.yml b/.github/workflows/r_package.yml
deleted file mode 100644
index 54b2798fa40a..000000000000
--- a/.github/workflows/r_package.yml
+++ /dev/null
@@ -1,184 +0,0 @@
-name: R-package
-
-on:
-  push:
-    branches:
-    - master
-  pull_request:
-    branches:
-    - master
-
-jobs:
-  test:
-    name: ${{ matrix.task }} (${{ matrix.os }}, ${{ matrix.compiler }}, R ${{ matrix.r_version }}, ${{ matrix.build_type }})
-    runs-on: ${{ matrix.os }}
-    timeout-minutes: 60
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          ################
-          # CMake builds #
-          ################
-          - os: ubuntu-latest
-            task: r-package
-            compiler: gcc
-            r_version: 3.6
-            build_type: cmake
-          - os: ubuntu-latest
-            task: r-package
-            compiler: gcc
-            r_version: 4.0
-            build_type: cmake
-          - os: ubuntu-latest
-            task: r-package
-            compiler: clang
-            r_version: 3.6
-            build_type: cmake
-          - os: ubuntu-latest
-            task: r-package
-            compiler: clang
-            r_version: 4.0
-            build_type: cmake
-          - os: macOS-latest
-            task: r-package
-            compiler: gcc
-            r_version: 3.6
-            build_type: cmake
-          - os: macOS-latest
-            task: r-package
-            compiler: gcc
-            r_version: 4.0
-            build_type: cmake
-          - os: macOS-latest
-            task: r-package
-            compiler: clang
-            r_version: 3.6
-            build_type: cmake
-          - os: macOS-latest
-            task: r-package
-            compiler: clang
-            r_version: 4.0
-            build_type: cmake
-          - os: windows-latest
-            task: r-package
-            compiler: MINGW
-            toolchain: MSYS
-            r_version: 4.0
-            build_type: cmake
-          # Visual Studio 2017
-          - os: windows-2016
-            task: r-package
-            compiler: MSVC
-            toolchain: MSVC
-            r_version: 3.6
-            build_type: cmake
-          # Visual Studio 2019
-          - os: windows-2019
-            task: r-package
-            compiler: MSVC
-            toolchain: MSVC
-            r_version: 4.0
-            build_type: cmake
-          ###############
-          # CRAN builds #
-          ###############
-          - os: windows-latest
-            task: r-package
-            compiler: MINGW
-            toolchain: MINGW
-            r_version: 3.6
-            build_type: cran
-          - os: windows-latest
-            task: r-package
-            compiler: MINGW
-            toolchain: MSYS
-            r_version: 4.0
-            build_type: cran
-          - os: ubuntu-latest
-            task: r-package
-            compiler: gcc
-            r_version: 4.0
-            build_type: cran
-          - os: macOS-latest
-            task: r-package
-            compiler: clang
-            r_version: 4.0
-            build_type: cran
-    steps:
-      - name: Prevent conversion of line endings on Windows
-        if: startsWith(matrix.os, 'windows')
-        shell: pwsh
-        run: git config --global core.autocrlf false
-      - name: Checkout repository
-        uses: actions/checkout@v2.3.4
-        with:
-          fetch-depth: 5
-          submodules: true
-      - name: Install pandoc
-        uses: r-lib/actions/setup-pandoc@v1
-      - name: Setup and run tests on Linux and macOS
-        if: matrix.os == 'macOS-latest' || matrix.os == 'ubuntu-latest'
-        shell: bash
-        run: |
-          export TASK="${{ matrix.task }}"
-          export COMPILER="${{ matrix.compiler }}"
-          export GITHUB_ACTIONS="true"
-          if [[ "${{ matrix.os }}" == "macOS-latest" ]]; then
-              export OS_NAME="macos"
-          elif [[ "${{ matrix.os }}" == "ubuntu-latest" ]]; then
-              export OS_NAME="linux"
-          fi
-          export BUILD_DIRECTORY="$GITHUB_WORKSPACE"
-          export R_VERSION="${{ matrix.r_version }}"
-          export R_BUILD_TYPE="${{ matrix.build_type }}"
-          $GITHUB_WORKSPACE/.ci/setup.sh
-          $GITHUB_WORKSPACE/.ci/test.sh
-      - name: Setup and run tests on Windows
-        if: startsWith(matrix.os, 'windows')
-        shell: pwsh -command ". {0}"
-        run: |
-          $env:BUILD_SOURCESDIRECTORY = $env:GITHUB_WORKSPACE
-          $env:TOOLCHAIN = "${{ matrix.toolchain }}"
-          $env:R_VERSION = "${{ matrix.r_version }}"
-          $env:R_BUILD_TYPE = "${{ matrix.build_type }}"
-          $env:COMPILER = "${{ matrix.compiler }}"
-          $env:GITHUB_ACTIONS = "true"
-          $env:TASK = "${{ matrix.task }}"
-          & "$env:GITHUB_WORKSPACE/.ci/test_windows.ps1"
-  test-r-sanitizers:
-    name: r-package (ubuntu-latest, R-devel, GCC ASAN/UBSAN)
-    timeout-minutes: 60
-    runs-on: ubuntu-latest
-    container: rhub/rocker-gcc-san
-    steps:
-      - name: Install Git before checkout
-        shell: bash
-        run: |
-          apt-get update
-          apt-get install --no-install-recommends -y git
-      - name: Checkout repository
-        uses: actions/checkout@v2.3.4
-        with:
-          fetch-depth: 5
-          submodules: true
-      - name: Install packages
-        shell: bash
-        run: |
-          Rscript -e "install.packages(c('R6', 'data.table', 'jsonlite', 'testthat'), repos = 'https://cran.r-project.org')"
-          sh build-cran-package.sh
-          Rdevel CMD INSTALL lightgbm_*.tar.gz || exit -1
-      - name: Run tests with sanitizers
-        shell: bash
-        run: |
-          cd R-package/tests
-          Rscriptdevel testthat.R 2>&1 > ubsan-tests.log
-          cat ubsan-tests.log
-          exit $(cat ubsan-tests.log | grep --count "runtime error")
-  all-successful:
-    # https://github.community/t/is-it-possible-to-require-all-github-actions-tasks-to-pass-without-enumerating-them/117957/4?u=graingert
-    runs-on: ubuntu-latest
-    needs: [test, test-r-sanitizers]
-    steps:
-    - name: Note that all tests succeeded
-      run: echo "🎉"
diff --git a/.github/workflows/r_solaris.yml b/.github/workflows/r_solaris.yml
deleted file mode 100644
index b11c0182312f..000000000000
--- a/.github/workflows/r_solaris.yml
+++ /dev/null
@@ -1,70 +0,0 @@
-name: Solaris CRAN check
-
-on:
-  repository_dispatch:
-    types: [gha_run_r_solaris]
-
-jobs:
-  test:
-    name: solaris-cran
-    timeout-minutes: 120
-    runs-on: ubuntu-latest
-    container: rocker/r-base
-    env:
-      SECRETS_WORKFLOW: ${{ secrets.WORKFLOW }}
-    steps:
-      - name: Install essential software before checkout
-        shell: bash
-        run: |
-          apt-get update
-          apt-get install --no-install-recommends -y \
-            curl \
-            git \
-            jq
-      - name: Checkout repository
-        uses: actions/checkout@v2.3.4
-        with:
-          fetch-depth: 5
-          submodules: true
-          repository: microsoft/LightGBM
-          ref: "refs/pull/${{ github.event.client_payload.pr_number }}/merge"
-      - name: Send init status
-        if: ${{ always() }}
-        run: |
-          $GITHUB_WORKSPACE/.ci/append_comment.sh \
-            "${{ github.event.client_payload.comment_number }}" \
-            "Workflow **${{ github.workflow }}** has been triggered! 🚀\r\n${GITHUB_SERVER_URL}/microsoft/LightGBM/actions/runs/${GITHUB_RUN_ID}"
-      - name: Run tests on Solaris
-        shell: bash
-        run: |
-          sh build-cran-package.sh || exit -1
-          apt-get install --no-install-recommends -y \
-              libcurl4-openssl-dev \
-              libxml2-dev \
-              libssl-dev
-          log_file="$GITHUB_WORKSPACE/rhub_logs.txt"
-          Rscript -e "install.packages('rhub', dependencies = c('Depends', 'Imports', 'LinkingTo'), repos = 'https://cran.r-project.org')"
-          Rscript $GITHUB_WORKSPACE/.ci/run_rhub_solaris_checks.R $(pwd)/lightgbm_*.tar.gz $log_file || exit -1
-      - name: Send final status
-        if: ${{ always() }}
-        run: |
-          $GITHUB_WORKSPACE/.ci/set_commit_status.sh "${{ github.workflow }}" "${{ job.status }}" "${{ github.event.client_payload.pr_sha }}"
-          body=""
-          while IFS= read -r line; do
-              platform=${line%@*}
-              url=${line#*@}
-              body="${body}**${platform}**: ${url}\r\n"
-          done < "$GITHUB_WORKSPACE/rhub_logs.txt" || true
-          body="${body}Reports also have been sent to LightGBM public e-mail: http://www.yopmail.com/lightgbm_rhub_checks\r\n"
-          body="${body}Status: ${{ job.status }}."
-          $GITHUB_WORKSPACE/.ci/append_comment.sh \
-            "${{ github.event.client_payload.comment_number }}" \
-            "$body"
-      - name: Rerun workflow-indicator
-        if: ${{ always() }}
-        run: |
-          bash $GITHUB_WORKSPACE/.ci/rerun_workflow.sh \
-            "optional_checks.yml" \
-            "${{ github.event.client_payload.pr_number }}" \
-            "${{ github.event.client_payload.pr_branch }}" \
-            || true
diff --git a/.github/workflows/r_valgrind.yml b/.github/workflows/r_valgrind.yml
deleted file mode 100644
index e9af3ae6fdc5..000000000000
--- a/.github/workflows/r_valgrind.yml
+++ /dev/null
@@ -1,61 +0,0 @@
-name: R valgrind tests
-
-on:
-  repository_dispatch:
-    types: [gha_run_r_valgrind]
-
-jobs:
-  test-r-valgrind:
-    name: r-package (ubuntu-latest, R-devel, valgrind)
-    timeout-minutes: 120
-    runs-on: ubuntu-latest
-    container: wch1/r-debug
-    env:
-      SECRETS_WORKFLOW: ${{ secrets.WORKFLOW }}
-    steps:
-      - name: Install essential software before checkout
-        shell: bash
-        run: |
-          apt-get update
-          apt-get install --no-install-recommends -y \
-            curl \
-            git \
-            jq
-      - name: Checkout repository
-        uses: actions/checkout@v2.3.4
-        with:
-          fetch-depth: 5
-          submodules: true
-          repository: microsoft/LightGBM
-          ref: "refs/pull/${{ github.event.client_payload.pr_number }}/merge"
-      - name: Send init status
-        if: ${{ always() }}
-        run: |
-          $GITHUB_WORKSPACE/.ci/set_commit_status.sh "${{ github.workflow }}" "pending" "${{ github.event.client_payload.pr_sha }}"
-          $GITHUB_WORKSPACE/.ci/append_comment.sh \
-            "${{ github.event.client_payload.comment_number }}" \
-            "Workflow **${{ github.workflow }}** has been triggered! 🚀\r\n${GITHUB_SERVER_URL}/microsoft/LightGBM/actions/runs/${GITHUB_RUN_ID}"
-      - name: Install packages
-        shell: bash
-        run: |
-          RDscriptvalgrind -e "install.packages(c('R6', 'data.table', 'jsonlite', 'testthat'), repos = 'https://cran.r-project.org')"
-          sh build-cran-package.sh
-          RDvalgrind CMD INSTALL --preclean --install-tests lightgbm_*.tar.gz || exit -1
-      - name: Run tests with valgrind
-        shell: bash
-        run: ./.ci/test_r_package_valgrind.sh
-      - name: Send final status
-        if: ${{ always() }}
-        run: |
-          $GITHUB_WORKSPACE/.ci/set_commit_status.sh "${{ github.workflow }}" "${{ job.status }}" "${{ github.event.client_payload.pr_sha }}"
-          $GITHUB_WORKSPACE/.ci/append_comment.sh \
-            "${{ github.event.client_payload.comment_number }}" \
-            "Status: ${{ job.status }}."
-      - name: Rerun workflow-indicator
-        if: ${{ always() }}
-        run: |
-          bash $GITHUB_WORKSPACE/.ci/rerun_workflow.sh \
-            "optional_checks.yml" \
-            "${{ github.event.client_payload.pr_number }}" \
-            "${{ github.event.client_payload.pr_branch }}" \
-            || true
diff --git a/.github/workflows/static_analysis.yml b/.github/workflows/static_analysis.yml
deleted file mode 100644
index 9f0faa12d1fd..000000000000
--- a/.github/workflows/static_analysis.yml
+++ /dev/null
@@ -1,85 +0,0 @@
-# contains non-functional tests, like checks on docs
-# and code style
-name: Static Analysis
-
-on:
-  push:
-    branches:
-    - master
-  pull_request:
-    branches:
-    - master
-
-env:
-  COMPILER: 'gcc'
-  CONDA_ENV: test-env
-  GITHUB_ACTIONS: 'true'
-  OS_NAME: 'linux'
-  PYTHON_VERSION: 3.9
-
-jobs:
-  test:
-    name: ${{ matrix.task }}
-    runs-on: ubuntu-latest
-    timeout-minutes: 60
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - task: lint
-          - task: check-docs
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v2.3.4
-        with:
-          fetch-depth: 5
-          submodules: false
-      - name: Setup and run tests
-        shell: bash
-        run: |
-          export TASK="${{ matrix.task }}"
-          export BUILD_DIRECTORY="$GITHUB_WORKSPACE"
-          export CONDA=${HOME}/miniconda
-          export PATH=${CONDA}/bin:$HOME/.local/bin:${PATH}
-          $GITHUB_WORKSPACE/.ci/setup.sh || exit -1
-          $GITHUB_WORKSPACE/.ci/test.sh || exit -1
-  r-check-docs:
-    name: r-package-check-docs
-    timeout-minutes: 60
-    runs-on: ubuntu-latest
-    container: rocker/verse
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v2.3.4
-        with:
-          fetch-depth: 5
-          submodules: true
-      - name: Install packages
-        shell: bash
-        run: |
-          Rscript -e "install.packages(c('R6', 'data.table', 'jsonlite', 'roxygen2', 'testthat'), repos = 'https://cran.r-project.org')"
-          sh build-cran-package.sh || exit -1
-          R CMD INSTALL --with-keep.source lightgbm_*.tar.gz || exit -1
-      - name: Test documentation
-        shell: bash --noprofile --norc {0}
-        run: |
-          Rscript --vanilla -e "roxygen2::roxygenize('R-package/', load = 'installed')" || exit -1
-          num_doc_files_changed=$(
-              git diff --name-only | grep --count -E "\.Rd|NAMESPACE"
-          )
-          if [[ ${num_doc_files_changed} -gt 0 ]]; then
-              echo "Some R documentation files have changed. Please re-generate them and commit those changes."
-              echo ""
-              echo "    sh build-cran-package.sh"
-              echo "    R CMD INSTALL --with-keep.source lightgbm_*.tar.gz"
-              echo "    Rscript -e \"roxygen2::roxygenize('R-package/', load = 'installed')\""
-              echo ""
-              exit -1
-          fi
-  all-successful:
-    # https://github.community/t/is-it-possible-to-require-all-github-actions-tasks-to-pass-without-enumerating-them/117957/4?u=graingert
-    runs-on: ubuntu-latest
-    needs: [test, r-check-docs]
-    steps:
-    - name: Note that all tests succeeded
-      run: echo "🎉"
diff --git a/.github/workflows/triggering_comments.yml b/.github/workflows/triggering_comments.yml
deleted file mode 100644
index 6803bf59fbc7..000000000000
--- a/.github/workflows/triggering_comments.yml
+++ /dev/null
@@ -1,42 +0,0 @@
-name: Triggering comments
-
-on:
-  issue_comment:
-    types: [created]
-
-jobs:
-  triggering-tests:
-    if: github.event.issue.pull_request && contains('OWNER,MEMBER,COLLABORATOR', github.event.comment.author_association) && startsWith(github.event.comment.body, '/gha run')
-    runs-on: ubuntu-latest
-    env:
-      SECRETS_WORKFLOW: ${{ secrets.WORKFLOW }}
-    steps:
-    - name: Checkout repository
-      uses: actions/checkout@v2.3.4
-      with:
-        fetch-depth: 5
-        submodules: false
-
-    - name: Trigger R valgrind tests
-      if: github.event.comment.body == '/gha run r-valgrind'
-      run: |
-        $GITHUB_WORKSPACE/.ci/trigger_dispatch_run.sh \
-          "${{ github.event.issue.pull_request.url }}" \
-          "${{ github.event.comment.id }}" \
-          "gha_run_r_valgrind"
-
-    - name: Trigger R artifact builds
-      if: github.event.comment.body == '/gha run build-r-artifacts'
-      run: |
-        $GITHUB_WORKSPACE/.ci/trigger_dispatch_run.sh \
-          "${{ github.event.issue.pull_request.url }}" \
-          "${{ github.event.comment.id }}" \
-          "gha_run_build_r_artifacts"
-
-    - name: Trigger R Solaris CRAN checks
-      if: github.event.comment.body == '/gha run r-solaris'
-      run: |
-        $GITHUB_WORKSPACE/.ci/trigger_dispatch_run.sh \
-          "${{ github.event.issue.pull_request.url }}" \
-          "${{ github.event.comment.id }}" \
-          "gha_run_r_solaris"