Switch code-coverage to Pcov

Author: ste93cry

.github/workflows/tests.yaml

@@ -53,7 +53,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
-          coverage: xdebug
+          coverage: pcov
           tools: flex
 
       - name: Setup Problem Matchers for PHPUnit