chore: added summary job to build-ci action

so that we have a job that can be referenced e.g. for required actions (matrix jobs can't be referenced by name, because the name is dynamically generated)

Author: jstucke

.github/workflows/build_ci.yml

@@ -85,3 +85,16 @@ jobs:
           verbose: true
         env:
           CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+  build-ci-complete:
+    name: Build CI Complete
+    needs: build-ci
+    runs-on: ubuntu-latest
+    if: always()
+    steps:
+      - name: Check build-ci matrix result
+        run: |
+          if [ "${{ needs.build-ci.result }}" != "success" ]; then
+            echo "Some build-ci matrix jobs failed!"
+            exit 1
+          fi
+          echo "All build-ci matrix jobs passed!"