fix: delete files is on main thread

Assets/Scripts/StorageManager.cs

@@ -73,7 +73,7 @@ public class StorageManager : MonoBehaviour
         int taskCount = deleteTasks.Count;
         Debug.Log($"There are {taskCount} files to delete", this);
 
-        Task.WhenAll(deleteTasks).ContinueWith(_ =>
+        Task.WhenAll(deleteTasks).ContinueWithOnMainThread(_ =>
         {
             Debug.Log($"all delete tasks are done", this);
             callback_OnFinish?.Invoke();