Update codecov/codecov-action action to v6 (#6441)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/checks.yml

@@ -97,7 +97,7 @@ jobs:
         uses: ./.github/actions/setup
       - name: Run coverage
         run: npm run coverage
-      - uses: codecov/codecov-action@v5
+      - uses: codecov/codecov-action@v6
         env:
           CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}