Revert "Use GH Action for codecov upload"

This reverts commit 11919bb.

Author: qtuantruong

.github/workflows/python-package.yml

@@ -50,6 +50,3 @@ jobs:
     - name: Test with pytest
       run: |
         python -m pytest --cov=cornac
-
-    - name: Upload coverage reports to Codecov
-      uses: codecov/codecov-action@v3