use different yml syntax

Author: dougbrn

.github/workflows/testing-and-coverage.yml

@@ -34,5 +34,5 @@ jobs:
         python -m pytest --cov=dask_nested --cov-report=xml
     - name: Upload coverage report to codecov
       uses: codecov/codecov-action@v5
-      with:
+      env:
         token: ${{ secrets.CODECOV_TOKEN }}