Revert "Upgrade to codecov/codecov-action@v4 (#186)" (#195)

This reverts commit 047eca0.

Author: Nusnus

.github/workflows/python-package.yml

@@ -67,10 +67,9 @@ jobs:
           tox --verbose --verbose -e "${{ matrix.python-version }}-unit"
 
       - name: Upload coverage reports to Codecov
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@v3
         with:
           fail_ci_if_error: true # optional (default = false)
-          token: ${{ secrets.CODECOV_TOKEN }} # required
           verbose: true # optional (default = false)
 
   Integration: