Use Xdebug instead of PCOV to work around #4622

Author: sebastianbergmann

.github/workflows/ci.yml

@@ -132,7 +132,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php-version }}
-          coverage: pcov
+          coverage: xdebug
           extensions: ${{ env.PHP_EXTENSIONS }}
           ini-values: ${{ env.PHP_INI_VALUES }}