[12.x] Define LARAVEL_START if not already defined (#57222)

* Define LARAVEL_START if not already defined

* Update ComposerScripts.php

---------

Co-authored-by: Taylor Otwell <[email protected]>

Author: cosmastech

src/Illuminate/Foundation/ComposerScripts.php

@@ -63,7 +63,9 @@ public static function prePackageUninstall(PackageEvent $event)
 
         require_once $vendorDir.'/autoload.php';
 
-        define('LARAVEL_START', microtime(true));
+        if (! defined('LARAVEL_START')) {
+            define('LARAVEL_START', microtime(true));
+        }
 
         /** @var Application $app */
         $app = require_once $bootstrapFile;