fix wrong namespace use

apps/backend/bootstrap/providers.php

@@ -1,7 +1,7 @@
 <?php
 
 return [
-    \apps\backend\app\Providers\AppServiceProvider::class,
-    \apps\backend\app\Providers\BroadcastServiceProvider::class,
-    \apps\backend\app\Providers\GateServiceProvider::class,
+    app\Providers\AppServiceProvider::class,
+    app\Providers\BroadcastServiceProvider::class,
+    app\Providers\GateServiceProvider::class,
 ];