add var_dumper

Author: LTaooo

composer.json

@@ -23,7 +23,9 @@
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "^3.22.0",
-        "phpunit/phpunit": "^10.2"
+        "phpunit/phpunit": "^10.2",
+        "symfony/var-dumper": "^6"
+
     },
     "scripts": {
         "post-root-package-install": [