Update codecov/codecov-action action to v4

Author: renovate[bot]

.github/workflows/codecov.yml

@@ -22,7 +22,7 @@ jobs:
           ruby-version: 3.1
       - run: bundle update
       - run: bundle exec rake
-      - uses: codecov/codecov-action@v3
+      - uses: codecov/codecov-action@v4
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           fail_ci_if_error: true