Made Github actions auto-cancel redundant jobs.

.github/workflows/docs.yml

@@ -12,6 +12,10 @@ on:
       - 'docs/**'
       - '.github/workflows/docs.yml'
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   docs:
     # OS must be the same as on djangoproject.com.

.github/workflows/linters.yml

@@ -10,6 +10,10 @@ on:
     paths-ignore:
       - 'docs/**'
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   flake8:
     name: flake8

.github/workflows/tests.yml

@@ -10,6 +10,10 @@ on:
     paths-ignore:
       - 'docs/**'
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   windows:
     runs-on: windows-latest