Add phpstan/extension-installer

Author: askdkc

composer.json

@@ -32,6 +32,7 @@
         "pestphp/pest": "^1.21|^2.0",
         "pestphp/pest-plugin-laravel": "^1.1",
         "pestphp/pest-plugin-livewire": "^1.0",
+        "phpstan/extension-installer": "^1.2",
         "phpunit/phpunit": "^9.5"
     },
     "autoload": {