[修复](事件): 事件的关闭就释放导致后续打开的事件对象出现空的问题

Author: AlianBlank

Runtime/UIForm.cs

@@ -298,13 +298,7 @@ public virtual void OnClose(bool isShutdown, object userData)
             gameObject.SetLayerRecursively(m_OriginalLayer);
             m_Available = false;
             Visible = false;
-            if (m_EventSubscriber != null)
-            {
-                m_EventSubscriber.UnSubscribeAll();
-                ReferencePool.Release(m_EventSubscriber);
-            }
-
-            m_EventSubscriber = null;
+            m_EventSubscriber?.UnSubscribeAll();
         }
 
         /// <summary>