Enable parallel execution for Coveralls GitHub Action

Author: harryswift01

.github/workflows/example_package_project-ci.yaml

@@ -35,6 +35,7 @@ jobs:
         uses: coverallsapp/github-action@5cbfd81b66ca5d10c19b062c04de0199c215fb6e # v2.3.7
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
+          parallel: true
 
   docs:
     runs-on: ubuntu-latest