🎨🔧👷 Wire in linters into the main workflow

This patch makes use of reusable workflows to embed the linting jobs
into the main pipeline. The technique allows having modularized CI
definitions stored in separate files but being voting in the
alls-green gate used in branch protection.

.github/workflows/ci.yml

@@ -33,6 +33,13 @@ env:
     PRE_COMMIT_COLOR
 
 jobs:
+  linters:
+    name: Linters
+    uses: ./.github/workflows/reusable-qa.yml
+    with:
+      cpython-pip-version: >-
+        ["main"]
+
   test:
     name: ${{ matrix.os }} / ${{ matrix.python-version }} / ${{ matrix.pip-version }}
     runs-on: ${{ matrix.os }}-latest
@@ -143,6 +150,7 @@ jobs:
     if: always()
 
     needs:
+      - linters
       - pypy
       - test
 

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

@@ -1,15 +1,7 @@
 name: QA
 
 on:
-  pull_request:
-  push:
-    branches:
-      - main
-    tags:
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}
-  cancel-in-progress: true
+  workflow_call:
 
 jobs:
   qa: