fix(ci): Fix Codecov coverage upload with explicit source and paths

- Specify explicit coverage source: --cov=src/ryandata_address_utils
- Use explicit output filename: --cov-report=xml:coverage.xml
- Add ./ prefix to file paths for Codecov action

Author: github-actions

.github/workflows/tests.yml

@@ -60,13 +60,13 @@ jobs:
 
       - name: Test with pytest
         run: |
-          uv run pytest --cov --cov-report=xml --junitxml=junit.xml
+          uv run pytest --cov=src/ryandata_address_utils --cov-report=xml:coverage.xml --junitxml=junit.xml
 
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v5
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
-          files: coverage.xml
+          files: ./coverage.xml
           flags: unittests-py${{ matrix.python-version }}
           fail_ci_if_error: true
           verbose: true
@@ -76,4 +76,4 @@ jobs:
         uses: codecov/test-results-action@v1
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
-          files: junit.xml
+          files: ./junit.xml