add "check" to ci (#21)

.github/workflows/ci.yml

@@ -72,9 +72,21 @@ jobs:
         file: ./coverage.xml
         env_vars: PYTHON,OS
 
+  check:  # This job does nothing and is only used for the branch protection
+    if: always()
+    needs: [lint, test]
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Decide whether the needed jobs succeeded or failed
+        uses: re-actors/alls-green@release/v1
+        id: all-green
+        with:
+          jobs: ${{ toJSON(needs) }}
+
   release:
     name: Release
-    needs: [lint, test]
+    needs: [check]
     if: "success() && startsWith(github.ref, 'refs/tags/')"
     runs-on: ubuntu-latest
     environment: release