Fix Python coverage reporting.

Apparently the fact that I want the coverage report to be XML isn't
enough of a hint that I want coverage.

.github/workflows/test.yml

@@ -15,7 +15,7 @@ jobs:
       - name: run tests
         run: |
           ./venv/scripts/activate
-          pytest --cov-report=xml tests
+          pytest --cov --cov-report=xml tests
 
       - name: Upload coverage reports to Codecov
         uses: codecov/codecov-action@v3

.gitignore

@@ -9,6 +9,7 @@ venv
 .vscode/settings.json
 dist/**
 /.coverage
+/coverage.xml
 # User-specific stuff
 .idea/
 .env