[Bug]: iOS 18.4.1 跳转到 Flutter 页面 直接卡死

### 请描述遇到的问题，以及您所期望的正确的结果

1、创建了一个 Flutter 项目：flutter create -t module flutter_module
2、注册路由
```
static Map routerMap ={
'mainPage': (settings, uniqueId) {
return CupertinoPageRoute(
settings: settings,
builder: (_) {
Map parameters = settings.arguments as Map? ?? {};
return MainPage(
parameters: parameters,
);
});
},
}
```
3、启动 FlutterBoost

```
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
setupFlutterEngine(application: application)
return true
}

private func setupFlutterEngine(application: UIApplication) {

let delegate = FlutterBoostDelegate()
// 启动 FlutterBoost
FlutterBoost.instance().setup(application, delegate: delegate) { [weak self] engine in
self?.flutterEngine = engine
}
}
```
界面跳转
```
let options = FlutterBoostRouteOptions()
options.pageName = "mainPage"
FlutterBoost.instance().open(options)
```

4、直接卡死在 pushFlutterRoute 这个方法的 let vc: FBFlutterViewContainer = FBFlutterViewContainer() 这一行代码
```
func pushFlutterRoute(_ options: FlutterBoostRouteOptions!) {
let vc: FBFlutterViewContainer = FBFlutterViewContainer()
......
}
```

**Flutter Version:**
Flutter 3.29.3 • channel stable • https://github.com/flutter/flutter.git
Framework • revision ea121f8859 (4 weeks ago) • 2025-04-11 19:10:07 +0000
Engine • revision cf56914b32
Tools • Dart 3.7.2 • DevTools 2.42.3

**flutter_boost Version：**
flutter_boost:
git:
url: 'https://github.com/alibaba/flutter_boost.git'
ref: '4.6.1'

**iOS Version:**
Xcode Version 16.3 (16E140)
iOS 18.4.1
手机 iPhone 15 Pro

每次 跳转 Flutter 页面 项目都直接卡死，怎么才能在18.4.1正常跑起来？测试在18.2 是正常的。

### 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

```
```

### 复现的平台

iOS

### Flutter SDK版本

3.29.3

### FlutterBoost版本

4.6.1

### 是否延迟初始化FlutterBoost

No

### 解决方案

Start by reproducing the freeze with Flutter 3.29.3, FlutterBoost 4.6.1, iOS 18.4.1, and the provided setup, then inspect pushFlutterRoute and the FBFlutterViewContainer initialization line. Compare the same navigation on iOS 18.2 and determine what prevents the Flutter page from opening. Done means the mainPage route opens normally on iOS 18.4.1 without hanging.

Written by the indexing model from the issue text.