Fix: provide CODECOV_TOKEN.

Author: aentinger

.github/workflows/unit-tests.yml

@@ -37,5 +37,6 @@ jobs:
       - name: Upload coverage report to Codecov
         uses: codecov/codecov-action@v4
         with:
+          token: ${{ secrets.CODECOV_TOKEN }}
           file: "${{ env.COVERAGE_DATA_PATH }}"
           fail_ci_if_error: true