chore: upgrade codecov-action to v7 (#204)

Author: sc-sonata-svg

.github/workflows/ci.yml

@@ -34,7 +34,7 @@ jobs:
       run: make test
     - name: Upload coverage
       if: matrix.django-version == 'pinned'
-      uses: codecov/codecov-action@v6
+      uses: codecov/codecov-action@v7
       with:
         token: ${{ secrets.CODECOV_TOKEN }}
         fail_ci_if_error: false