Revert back to Xdebug for code-coverage

Author: ste93cry

.github/workflows/tests.yaml

@@ -55,7 +55,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
-          coverage: pcov
+          coverage: xdebug
           tools: flex
 
       - name: Setup Problem Matchers for PHPUnit