chore(ci): enable xdebug for code coverage in docs workflow

Author: gaelreyrol

.github/workflows/docs.yml

@@ -17,7 +17,7 @@ jobs:
         with:
           php-version: '8.4'
           extensions: mbstring, pdo, pdo_sqlite
-          coverage: none
+          coverage: xdebug
       - name: Get composer cache directory
         id: composercache
         run: echo "dir=$(composer config cache-files-dir)" >> "$GITHUB_OUTPUT"