Add Codecov token to CI

Author: gdalle

.github/workflows/ci.yml

@@ -56,6 +56,8 @@ jobs:
       - uses: codecov/codecov-action@v4
         with:
           file: lcov.info
+          token: ${{ secrets.CODECOV_TOKEN }       
+          fail_ci_if_error: true
   docs:
     name: Documentation
     runs-on: ubuntu-latest