chore: use pcov on CI

Author: Justintime50

.github/workflows/ci.yml

@@ -30,7 +30,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.phpversion }}
-          coverage: xdebug
+          coverage: pcov
       - name: get composer cache directory
         id: composer-cache
         run: echo "::set-output name=dir::$(composer config cache-files-dir)"