Cancel stale executions (#138)

https://docs.github.com/en/actions/using-jobs/using-concurrency#example-only-cancel-in-progress-jobs-or-runs-for-the-current-workflow

.github/workflows/core_tests.yml

@@ -6,6 +6,9 @@ on:
     paths: [".github/**", "core/**"]
   pull_request:
     paths: [".github/**", "core/**"]
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 jobs:
   test:
     name: Julia ${{ matrix.julia_version }} - ${{ matrix.os }} - ${{ matrix.arch }}

.github/workflows/docs.yml

@@ -4,6 +4,9 @@ on:
     branches: [main]
     paths-ignore: [".teamcity/**"]
   pull_request:
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 jobs:
   publish:
     name: Docs Julia ${{ matrix.julia_version }} - Python ${{ matrix.python_version }}  - ${{ matrix.arch }}

.github/workflows/python_lint.yml

@@ -6,6 +6,9 @@ on:
     paths: [".github/**", "python/**"]
   pull_request:
     paths: [".github/**", "python/**"]
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 jobs:
   lint:
     name: Python ${{ matrix.python_version }} - ${{ matrix.os }} - ${{ matrix.arch }}

.github/workflows/python_tests.yml

@@ -6,6 +6,9 @@ on:
     paths: [".github/**", "python/**"]
   pull_request:
     paths: [".github/**", "python/**"]
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 jobs:
   test:
     name: Python ${{ matrix.python_version }} - ${{ matrix.os }} - ${{ matrix.arch }}