CI: Update codecov action to version 3

* Replace codecov/codecov-action@v4 with codecov/codecov-action@v3 in the tests workflow file.

Author: ityaozm@gmail.com

.github/workflows/tests.yml

@@ -38,8 +38,9 @@ jobs:
         run: composer test-c
 
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@v3
         with:
+          files: ./clover.xml
           token: ${{ secrets.CODECOV_TOKEN }} # not required for public repos
-          fail_ci_if_error: false # optional (default = false)
+          fail_ci_if_error: true # optional (default = false)
           verbose: true # optional (default = false)