diff --git a/.github/actions/godot-cache/action.yml b/.github/actions/godot-cache-restore/action.yml
similarity index 77%
rename from .github/actions/godot-cache/action.yml
rename to .github/actions/godot-cache-restore/action.yml
index e54e6064a73a..614a98330d47 100644
--- a/.github/actions/godot-cache/action.yml
+++ b/.github/actions/godot-cache-restore/action.yml
@@ -1,5 +1,5 @@
-name: Setup Godot build cache
-description: Setup Godot build cache.
+name: Restore Godot build cache
+description: Restore Godot build cache.
 inputs:
   cache-name:
     description: The cache base name (job name by default).
@@ -10,9 +10,8 @@ inputs:
 runs:
   using: "composite"
   steps:
-    # Upload cache on completion and check it out now
-    - name: Load .scons_cache directory
-      uses: actions/cache@v4
+    - name: Restore .scons_cache directory
+      uses: actions/cache/restore@v4
       with:
         path: ${{inputs.scons-cache}}
         key: ${{inputs.cache-name}}-${{env.GODOT_BASE_BRANCH}}-${{github.ref}}-${{github.sha}}
diff --git a/.github/actions/godot-cache-save/action.yml b/.github/actions/godot-cache-save/action.yml
new file mode 100644
index 000000000000..bb3f18ad85a1
--- /dev/null
+++ b/.github/actions/godot-cache-save/action.yml
@@ -0,0 +1,17 @@
+name: Save Godot build cache
+description: Save Godot build cache.
+inputs:
+  cache-name:
+    description: The cache base name (job name by default).
+    default: "${{github.job}}"
+  scons-cache:
+    description: The scons cache path.
+    default: "${{github.workspace}}/.scons-cache/"
+runs:
+  using: "composite"
+  steps:
+    - name: Save .scons_cache directory
+      uses: actions/cache/save@v4
+      with:
+        path: ${{inputs.scons-cache}}
+        key: ${{inputs.cache-name}}-${{env.GODOT_BASE_BRANCH}}-${{github.ref}}-${{github.sha}}
diff --git a/.github/actions/godot-deps/action.yml b/.github/actions/godot-deps/action.yml
index 881eb7d1f683..cac72c436ed3 100644
--- a/.github/actions/godot-deps/action.yml
+++ b/.github/actions/godot-deps/action.yml
@@ -23,5 +23,5 @@ runs:
       shell: bash
       run: |
         python -c "import sys; print(sys.version)"
-        python -m pip install scons==4.4.0
+        python -m pip install scons==4.7.0
         scons --version
diff --git a/.github/workflows/android_builds.yml b/.github/workflows/android_builds.yml
index ee4e34c71e09..b1233391980c 100644
--- a/.github/workflows/android_builds.yml
+++ b/.github/workflows/android_builds.yml
@@ -14,27 +14,20 @@ concurrency:
 
 jobs:
   android-template:
-    runs-on: "ubuntu-20.04"
+    runs-on: "ubuntu-24.04"
     name: Template (target=release, tools=no)
 
     steps:
       - uses: actions/checkout@v4
 
-      # Azure repositories are not reliable, we need to prevent azure giving us packages.
-      - name: Make apt sources.list use the default Ubuntu repositories
-        run: |
-          sudo rm -f /etc/apt/sources.list.d/*
-          sudo cp -f misc/ci/sources.list /etc/apt/sources.list
-          sudo apt-get update
-
-      - name: Set up Java 11
+      - name: Set up Java 17
         uses: actions/setup-java@v4
         with:
           distribution: temurin
-          java-version: 11
+          java-version: 17
 
-      - name: Setup Godot build cache
-        uses: ./.github/actions/godot-cache
+      - name: Restore Godot build cache
+        uses: ./.github/actions/godot-cache-restore
         continue-on-error: true
 
       - name: Setup python and scons
@@ -56,6 +49,10 @@ jobs:
           target: release
           tools: false
 
+      - name: Save Godot build cache
+        uses: ./.github/actions/godot-cache-save
+        continue-on-error: true
+
       - name: Generate Godot templates
         run: |
           cd platform/android/java
diff --git a/.github/workflows/ios_builds.yml b/.github/workflows/ios_builds.yml
index 8c65167961cf..00fcac40ec90 100644
--- a/.github/workflows/ios_builds.yml
+++ b/.github/workflows/ios_builds.yml
@@ -20,8 +20,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Setup Godot build cache
-        uses: ./.github/actions/godot-cache
+      - name: Restore Godot build cache
+        uses: ./.github/actions/godot-cache-restore
         continue-on-error: true
 
       - name: Setup python and scons
@@ -35,5 +35,9 @@ jobs:
           target: release
           tools: false
 
+      - name: Save Godot build cache
+        uses: ./.github/actions/godot-cache-save
+        continue-on-error: true
+
       - name: Upload artifact
         uses: ./.github/actions/upload-artifact
diff --git a/.github/workflows/javascript_builds.yml b/.github/workflows/javascript_builds.yml
index 11e25da2f96c..381e1f6185d7 100644
--- a/.github/workflows/javascript_builds.yml
+++ b/.github/workflows/javascript_builds.yml
@@ -16,7 +16,7 @@ concurrency:
 
 jobs:
   javascript-template:
-    runs-on: "ubuntu-20.04"
+    runs-on: "ubuntu-24.04"
     name: Template (target=release, tools=no)
 
     steps:
@@ -33,8 +33,8 @@ jobs:
         run: |
           emcc -v
 
-      - name: Setup Godot build cache
-        uses: ./.github/actions/godot-cache
+      - name: Restore Godot build cache
+        uses: ./.github/actions/godot-cache-restore
         continue-on-error: true
 
       - name: Setup python and scons
@@ -48,5 +48,9 @@ jobs:
           target: release
           tools: false
 
+      - name: Save Godot build cache
+        uses: ./.github/actions/godot-cache-save
+        continue-on-error: true
+
       - name: Upload artifact
         uses: ./.github/actions/upload-artifact
diff --git a/.github/workflows/linux_builds.yml b/.github/workflows/linux_builds.yml
index 6bcb2ee7a6f1..d097b42e34ac 100644
--- a/.github/workflows/linux_builds.yml
+++ b/.github/workflows/linux_builds.yml
@@ -14,7 +14,8 @@ concurrency:
 
 jobs:
   build-linux:
-    runs-on: "ubuntu-20.04"
+    # Stay one LTS before latest to increase portability of Linux artifacts.
+    runs-on: "ubuntu-22.04"
     name: ${{ matrix.name }}
     strategy:
       fail-fast: false
@@ -54,17 +55,23 @@ jobs:
       - name: Linux dependencies
         shell: bash
         run: |
-          # Azure repositories are not reliable, we need to prevent azure giving us packages.
-          sudo rm -f /etc/apt/sources.list.d/*
-          sudo cp -f misc/ci/sources.list /etc/apt/sources.list
+          # Azure repositories are flaky, remove them.
+          sudo rm -f /etc/apt/sources.list.d/{azure,microsoft}*
           sudo apt-get update
-          # The actual dependencies
-          sudo apt-get install build-essential pkg-config libx11-dev libxcursor-dev \
-              libxinerama-dev libgl1-mesa-dev libglu-dev libasound2-dev libpulse-dev \
-              libdbus-1-dev libudev-dev libxi-dev libxrandr-dev yasm xvfb wget unzip
+          # The actual dependencies.
+          sudo apt-get install --no-install-recommends build-essential pkg-config libx11-dev \
+              libxcursor-dev libxinerama-dev libgl1-mesa-dev libglu-dev libasound2-dev \
+              libpulse-dev libdbus-1-dev libudev-dev libxi-dev libxrandr-dev yasm xvfb wget unzip \
+              libspeechd-dev speech-dispatcher
 
-      - name: Setup Godot build cache
-        uses: ./.github/actions/godot-cache
+      - name: Free disk space on runner
+        run: |
+          echo "Disk usage before:" && df -h
+          sudo rm -rf /usr/local/lib/android
+          echo "Disk usage after:" && df -h
+
+      - name: Restore Godot build cache
+        uses: ./.github/actions/godot-cache-restore
         with:
           cache-name: ${{ matrix.cache-name }}
         continue-on-error: true
@@ -83,6 +90,12 @@ jobs:
           target: ${{ matrix.target }}
           tools: ${{ matrix.tools }}
 
+      - name: Save Godot build cache
+        uses: ./.github/actions/godot-cache-save
+        with:
+          cache-name: ${{ matrix.cache-name }}
+        continue-on-error: true
+
       # Generate mono glue
       - name: Generate Mono glue code
         if: ${{ matrix.build-mono }}
@@ -103,9 +116,9 @@ jobs:
       - name: Download test project
         if: ${{ matrix.test }}
         run: |
-          wget https://github.com/godotengine/regression-test-project/archive/3.x.zip
-          unzip 3.x.zip
-          mv "regression-test-project-3.x" "test_project"
+          wget https://github.com/godotengine/regression-test-project/archive/3.5.zip
+          unzip 3.5.zip
+          mv "regression-test-project-3.5" "test_project"
 
       # Editor is quite complicated piece of software, so it is easy to introduce bug here
       - name: Open and close editor
diff --git a/.github/workflows/macos_builds.yml b/.github/workflows/macos_builds.yml
index 1790284c3050..021f09a6f124 100644
--- a/.github/workflows/macos_builds.yml
+++ b/.github/workflows/macos_builds.yml
@@ -34,8 +34,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Setup Godot build cache
-        uses: ./.github/actions/godot-cache
+      - name: Restore Godot build cache
+        uses: ./.github/actions/godot-cache-restore
         with:
           cache-name: ${{ matrix.cache-name }}
         continue-on-error: true
@@ -51,6 +51,12 @@ jobs:
           target: ${{ matrix.target }}
           tools: ${{ matrix.tools }}
 
+      - name: Save Godot build cache
+        uses: ./.github/actions/godot-cache-save
+        with:
+          cache-name: ${{ matrix.cache-name }}
+        continue-on-error: true
+
       - name: Prepare artifact
         run: |
           strip bin/godot.*
diff --git a/.github/workflows/server_builds.yml b/.github/workflows/server_builds.yml
index 9f34041ce23a..02e2ea9acdae 100644
--- a/.github/workflows/server_builds.yml
+++ b/.github/workflows/server_builds.yml
@@ -14,7 +14,8 @@ concurrency:
 
 jobs:
   build-server:
-    runs-on: "ubuntu-20.04"
+    # Stay one LTS before latest to increase portability of Linux artifacts.
+    runs-on: "ubuntu-22.04"
     name: ${{ matrix.name }}
     strategy:
       fail-fast: false
@@ -36,17 +37,17 @@ jobs:
       - name: Linux dependencies
         shell: bash
         run: |
-          # Azure repositories are not reliable, we need to prevent azure giving us packages.
-          sudo rm -f /etc/apt/sources.list.d/*
-          sudo cp -f misc/ci/sources.list /etc/apt/sources.list
+          # Azure repositories are flaky, remove them.
+          sudo rm -f /etc/apt/sources.list.d/{azure,microsoft}*
           sudo apt-get update
-          # The actual dependencies
-          sudo apt-get install build-essential pkg-config libx11-dev libxcursor-dev \
-              libxinerama-dev libgl1-mesa-dev libglu-dev libasound2-dev libpulse-dev \
-              libdbus-1-dev libudev-dev libxi-dev libxrandr-dev yasm xvfb wget unzip
+          # The actual dependencies.
+          sudo apt-get install --no-install-recommends build-essential pkg-config libx11-dev \
+              libxcursor-dev libxinerama-dev libgl1-mesa-dev libglu-dev libasound2-dev \
+              libpulse-dev libdbus-1-dev libudev-dev libxi-dev libxrandr-dev yasm xvfb wget unzip \
+              libspeechd-dev speech-dispatcher
 
-      - name: Setup Godot build cache
-        uses: ./.github/actions/godot-cache
+      - name: Restore Godot build cache
+        uses: ./.github/actions/godot-cache-restore
         with:
           cache-name: ${{ matrix.cache-name }}
         continue-on-error: true
@@ -61,3 +62,9 @@ jobs:
           platform: server
           target: ${{ matrix.target }}
           tools: ${{ matrix.tools }}
+
+      - name: Save Godot build cache
+        uses: ./.github/actions/godot-cache-save
+        with:
+          cache-name: ${{ matrix.cache-name }}
+        continue-on-error: true
diff --git a/.github/workflows/static_checks.yml b/.github/workflows/static_checks.yml
index 082ebdebfa56..4d4f949e3eb7 100644
--- a/.github/workflows/static_checks.yml
+++ b/.github/workflows/static_checks.yml
@@ -9,26 +9,25 @@ concurrency:
 jobs:
   static-checks:
     name: Static Checks (clang-format, black format, file format, documentation checks)
-    runs-on: ubuntu-20.04
+    runs-on: "ubuntu-24.04"
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
-      # Azure repositories are not reliable, we need to prevent Azure giving us packages.
-      - name: Make apt sources.list use the default Ubuntu repositories
+      - name: Install dependencies
         run: |
-          sudo rm -f /etc/apt/sources.list.d/*
-          sudo cp -f misc/ci/sources.list /etc/apt/sources.list
-          wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-          sudo apt-add-repository "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-15 main"
+          # Azure repositories are flaky, remove them.
+          sudo rm -f /etc/apt/sources.list.d/{azure,microsoft}*
           sudo apt-get update
+          sudo apt-get install -qq dos2unix libxml2-utils python3-pip moreutils
+          sudo update-alternatives --remove-all clang-format || true
+          sudo update-alternatives --install /usr/bin/clang-format clang-format /usr/bin/clang-format-16 100
+          sudo pip3 install black==24.10.0 pygments
 
-      - name: Install dependencies
+      # This needs to happen before Python and npm execution; it must happen before any extra files are written.
+      - name: .gitignore checks (gitignore_check.sh)
         run: |
-          sudo apt-get install -qq dos2unix clang-format-15 libxml2-utils python3-pip moreutils
-          sudo update-alternatives --remove-all clang-format || true
-          sudo update-alternatives --install /usr/bin/clang-format clang-format /usr/bin/clang-format-15 100
-          sudo pip3 install black==22.3.0 pygments
+          bash ./misc/scripts/gitignore_check.sh
 
       - name: File formatting checks (file_format.sh)
         run: |
diff --git a/.github/workflows/windows_builds.yml b/.github/workflows/windows_builds.yml
index 99b02a05261e..339d5a734cfb 100644
--- a/.github/workflows/windows_builds.yml
+++ b/.github/workflows/windows_builds.yml
@@ -37,8 +37,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Setup Godot build cache
-        uses: ./.github/actions/godot-cache
+      - name: Restore Godot build cache
+        uses: ./.github/actions/godot-cache-restore
         with:
           cache-name: ${{ matrix.cache-name }}
         continue-on-error: true
@@ -57,6 +57,12 @@ jobs:
           target: ${{ matrix.target }}
           tools: ${{ matrix.tools }}
 
+      - name: Save Godot build cache
+        uses: ./.github/actions/godot-cache-save
+        with:
+          cache-name: ${{ matrix.cache-name }}
+        continue-on-error: true
+
       - name: Prepare artifact
         run: |
           Remove-Item bin/* -Include *.exp,*.lib,*.pdb -Force
diff --git a/doc/translations/extract.py b/doc/translations/extract.py
index 6208468509f6..e14c6d1b5c3c 100644
--- a/doc/translations/extract.py
+++ b/doc/translations/extract.py
@@ -59,6 +59,7 @@
 sys.modules["_elementtree"] = None
 import xml.etree.ElementTree as ET
 
+
 ## override the parser to get the line number
 class LineNumberingParser(ET.XMLParser):
     def _start(self, *args, **kwargs):
diff --git a/editor/editor_builders.py b/editor/editor_builders.py
index 54fc20ca4bcb..bcd1bc071f76 100644
--- a/editor/editor_builders.py
+++ b/editor/editor_builders.py
@@ -3,6 +3,7 @@
 All such functions are invoked in a subprocess on Windows to prevent build flakiness.
 
 """
+
 import os
 import os.path
 import shutil
diff --git a/editor/icons/editor_icons_builders.py b/editor/icons/editor_icons_builders.py
index ce6b9a8686ab..dd910a6810b8 100644
--- a/editor/icons/editor_icons_builders.py
+++ b/editor/icons/editor_icons_builders.py
@@ -3,6 +3,7 @@
 All such functions are invoked in a subprocess on Windows to prevent build flakiness.
 
 """
+
 import os
 from platform_methods import subprocess_main
 from compat import StringIO
diff --git a/gles_builders.py b/gles_builders.py
index f43b3b850088..a8effa75fd06 100644
--- a/gles_builders.py
+++ b/gles_builders.py
@@ -3,6 +3,7 @@
 All such functions are invoked in a subprocess on Windows to prevent build flakiness.
 
 """
+
 from platform_methods import subprocess_main
 import re
 
diff --git a/main/main_builders.py b/main/main_builders.py
index 6e5a5ceede4f..d8334f3b7a58 100644
--- a/main/main_builders.py
+++ b/main/main_builders.py
@@ -3,6 +3,7 @@
 All such functions are invoked in a subprocess on Windows to prevent build flakiness.
 
 """
+
 from platform_methods import subprocess_main
 from compat import byte_to_str
 from collections import OrderedDict
diff --git a/misc/scripts/file_format.sh b/misc/scripts/file_format.sh
index 86a84cf30701..d6c671783782 100755
--- a/misc/scripts/file_format.sh
+++ b/misc/scripts/file_format.sh
@@ -28,7 +28,9 @@ while IFS= read -rd '' f; do
         continue
     elif [[ "$f" == *"po" ]]; then
         continue
-    elif [[ "$f" == "thirdparty"* ]]; then
+    elif [[ "$f" == "thirdparty/"* ]]; then
+        continue
+    elif [[ "$f" == *"/thirdparty/"* ]]; then
         continue
     elif [[ "$f" == "platform/android/java/lib/src/com/google"* ]]; then
         continue
diff --git a/misc/scripts/gitignore_check.sh b/misc/scripts/gitignore_check.sh
new file mode 100644
index 000000000000..f162e25391b0
--- /dev/null
+++ b/misc/scripts/gitignore_check.sh
@@ -0,0 +1,26 @@
+set -uo pipefail
+shopt -s globstar
+
+echo -e ".gitignore validation..."
+
+# Get a list of files that exist in the repo but are ignored.
+
+# The --verbose flag also includes files un-ignored via ! prefixes.
+# We filter those out with a somewhat awkward `awk` directive.
+	# (Explanation: Split each line by : delimiters,
+	# see if the actual gitignore line shown in the third field starts with !,
+	# if it doesn't, print it.)
+
+# ignorecase for the sake of Windows users.
+
+output=$(git -c core.ignorecase=true check-ignore --verbose --no-index **/* | \
+    awk -F ':' '{ if ($3 !~ /^!/) print $0 }')
+
+# Then we take this result and return success if it's empty.
+if [ -z "$output" ]; then
+    exit 0
+else
+	# And print the result if it isn't.
+    echo "$output"
+    exit 1
+fi
diff --git a/modules/denoise/resource_to_cpp.py b/modules/denoise/resource_to_cpp.py
index 6c8327735599..307ea0ee7ded 100644
--- a/modules/denoise/resource_to_cpp.py
+++ b/modules/denoise/resource_to_cpp.py
@@ -19,6 +19,7 @@
 import os
 from array import array
 
+
 # Generates a C++ file from the specified binary resource file
 def generate(in_path, out_path):
 
diff --git a/modules/gdnative/gdnative_builders.py b/modules/gdnative/gdnative_builders.py
index d44bf452144a..fa9c42239456 100644
--- a/modules/gdnative/gdnative_builders.py
+++ b/modules/gdnative/gdnative_builders.py
@@ -3,6 +3,7 @@
 All such functions are invoked in a subprocess on Windows to prevent build flakiness.
 
 """
+
 import json
 from platform_methods import subprocess_main
 
diff --git a/platform/osx/platform_osx_builders.py b/platform/osx/platform_osx_builders.py
index 953ed479db36..d60f78884a09 100644
--- a/platform/osx/platform_osx_builders.py
+++ b/platform/osx/platform_osx_builders.py
@@ -3,6 +3,7 @@
 All such functions are invoked in a subprocess on Windows to prevent build flakiness.
 
 """
+
 import os
 from platform_methods import subprocess_main
 
diff --git a/platform/windows/platform_windows_builders.py b/platform/windows/platform_windows_builders.py
index 22e33b51b490..0d518e31c437 100644
--- a/platform/windows/platform_windows_builders.py
+++ b/platform/windows/platform_windows_builders.py
@@ -3,6 +3,7 @@
 All such functions are invoked in a subprocess on Windows to prevent build flakiness.
 
 """
+
 import os
 from platform_methods import subprocess_main
 
diff --git a/platform/x11/platform_x11_builders.py b/platform/x11/platform_x11_builders.py
index 5884f8e16118..632bafce020d 100644
--- a/platform/x11/platform_x11_builders.py
+++ b/platform/x11/platform_x11_builders.py
@@ -3,6 +3,7 @@
 All such functions are invoked in a subprocess on Windows to prevent build flakiness.
 
 """
+
 import os
 from platform_methods import subprocess_main