Update test suite to use PCOV to avoid segfault with Xdebug 3.4.2

Author: clue

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
       - uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
-          coverage: xdebug
+          coverage: ${{ matrix.php < 8.0 && 'xdebug' || 'pcov' }}
           ini-file: development
       - run: composer install
       - run: docker run --net=host -d redis