Fix condition to trigger GitAction workflow (2) (#46)

.github/workflows/generate-single-openapi-spec.yaml

@@ -39,9 +39,11 @@ jobs:
     name: Commit and push single-file OpenAPI specifications
     runs-on: ubuntu-latest
     needs: build-single-spec
-    if: github.event.pull_request.head.repo.full_name == github.repository
+    if: github.event_name == 'push'
     steps:
       - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.ref_name }}
       - uses: actions/download-artifact@v4
         with:
           name: artifacts-${{ github.workflow }}-${{ github.run_id }}-${{ github.run_number }}