fix wrong namespace use

apps/backend/app/Http/Controllers/EventsController.php

@@ -2,10 +2,10 @@
 
 namespace app\Http\Controllers;
 
-use apps\backend\app\Mail\EventParticipationCancelledMail;
-use apps\backend\app\Models\Event;
-use apps\backend\app\Models\Task;
-use apps\backend\app\Notifications\EventDeleted;
+use app\Mail\EventParticipationCancelledMail;
+use app\Models\Event;
+use app\Models\Task;
+use app\Notifications\EventDeleted;
 use Carbon\Carbon;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Request;