chore(deps): update codecov/codecov-action action to v7

Author: renovate[bot]

.github/workflows/_test.yml

@@ -33,7 +33,7 @@ jobs:
         run: uv run --locked tox -e tests
 
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v7
         with:
           name: ${{ inputs.python-version }}/${{ inputs.runs-on }}
           files: cov.xml