Worked around macOS coveralls bug on homebrew

Author: agronholm

.github/workflows/test.yml

@@ -109,6 +109,7 @@ jobs:
     - name: Generate coverage report
       run: coverage xml
     - name: Upload Coverage
+      if: runner.os != 'macOS'
       uses: coverallsapp/github-action@v2
       with:
         parallel: true