CI: detect test matrix failure correctly

We were missing always(), and use the alls-green action to verify the status of
the test matrix jobs. Without always() the check step was being skipped
whenever a test failed. 🤦

.github/workflows/ci.yml

@@ -120,10 +120,12 @@ jobs:
     name: Test matrix status
     runs-on: ubuntu-latest
     needs: [test]
+    if: always()
     steps:
-      - name: Check build matrix status
-        if: needs.test.result != 'success'
-        run: exit 1
+    - name: Decide whether the needed jobs succeeded or failed
+      uses: re-actors/alls-green@release/v1
+      with:
+        jobs: ${{ toJSON(needs) }}
 
   pre-deploy:
     name: Pre-Deploy

CHANGES/327.misc

@@ -0,0 +1 @@
+Updated the CI runs to better check for test results and to avoid deprecated syntax.