[Bug]: iOS，当push2个webview后再侧滑返回，上个webview页面出现白屏

### 请描述遇到的问题，以及您所期望的正确的结果

侧滑pop返回没有白屏现象

### 请说明如何操作会遇到上述问题

_No response_

### 在下面填入关键复现代码

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### 复现的平台

iOS

### Flutter SDK版本

Flutter 3.3.1

### FlutterBoost版本

4.3.0

### 是否延迟初始化FlutterBoost

No

### 解决方案

No source file, test, or reproduction code is named. Start by reproducing the iOS flow with Flutter 3.3.1 and FlutterBoost 4.3.0: push two webviews, then swipe back. Investigate the FlutterBoost iOS navigation and webview handling; done means the previous webview remains visible after the pop.

Written by the indexing model from the issue text.