chore(deps): update codecov/codecov-action action to v6

Author: renovate[bot]

.github/workflows/test.yaml

@@ -32,6 +32,6 @@ jobs:
       - name: Test with pytest
         run: nox -db uv
       - name: Upload coverage reports to Codecov
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           use_oidc: ${{ !(github.event_name == 'pull_request' && github.event.pull_request.head.repo.fork) }}