Conditional coverage report on Pull Request

Author: tdstein

.github/workflows/main.yml

@@ -35,7 +35,7 @@ jobs:
     - run: make lint
     - run: python setup.py --version
     - run: make test-${{ matrix.python-version }}
-    - if: matrix.python-version == '3.8'
+    - if: github.event_name == 'pull_request' && matrix.python-version == '3.8'
       uses: orgoro/coverage@v3
       with:
         coverageFile: coverage.xml