🎨🧪 Wire linters into the main CI workflow

This patch makes the quality workflow definition into reusable. It
doesn't need to track the same triggers and conditions as the main
one. Additionally, the `alls-green` check can now take into account
the outcome of linting making it possible to only have one job in
the branch protection.

.github/workflows/quality.yml → .github/workflows/reusable-quality.yml

@@ -4,12 +4,7 @@
 name: "Quality"
 
 on:
-  push:
-    branches:
-      - master
-      - nedbat/*
-  pull_request:
-  workflow_dispatch:
+  workflow_call:
 
 defaults:
   run:
@@ -21,10 +16,6 @@ env:
 permissions:
   contents: read
 
-concurrency:
-  group: "${{ github.workflow }}-${{ github.ref }}"
-  cancel-in-progress: true
-
 jobs:
   lint:
     name: "Pylint etc"

.github/workflows/testsuite.yml

@@ -3,6 +3,9 @@
 
 name: "Tests"
 
+if: >-  # Don't run pipeline if the branch name includes "-notests"
+  !contains(github.ref, '-notests')
+
 on:
   push:
     branches:
@@ -28,11 +31,13 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  linters:
+    name: Quality
+    uses: ./.github/workflows/reusable-quality.yml
+
   tests:
     name: "${{ matrix.python-version }} on ${{ matrix.os }}"
     runs-on: "${{ matrix.os }}-latest"
-    # Don't run tests if the branch name includes "-notests"
-    if: "!contains(github.ref, '-notests')"
     strategy:
       matrix:
         os:
@@ -91,9 +96,8 @@ jobs:
   # https://github.com/orgs/community/discussions/33579
   success:
     name: Tests successful
-    # The tests didn't run if the branch name includes "-notests"
-    if: "!contains(github.ref, '-notests')"
     needs:
+      - linters
       - tests
     runs-on: ubuntu-latest
     steps: