Add alls-green job (#2544)

.github/workflows/test-suite.yml

@@ -11,7 +11,7 @@ jobs:
   tests:
     name: "Python ${{ matrix.python-version }} ${{ matrix.os }}"
     runs-on: "${{ matrix.os }}"
-    timeout-minutes: 30
+    timeout-minutes: 10
     strategy:
       fail-fast: false
       matrix:
@@ -38,3 +38,14 @@ jobs:
       - name: "Enforce coverage"
         run: "scripts/coverage"
         shell: bash
+
+  # https://github.com/marketplace/actions/alls-green#why
+  check:
+    if: always()
+    needs: [tests]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Decide whether the needed jobs succeeded or failed
+        uses: re-actors/alls-green@release/v1
+        with:
+          jobs: ${{ toJSON(needs) }}