Fixes regression of RCTWindowFrameDidChangeNotification not fired (#4…

…7236)

Summary:
Fixes #47234. regression from 391680f#diff-b7fda5d350ac535115fa683faa7317b43aa11f3448f95266ef9ff051c3753a6fL63

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## Changelog:

[IOS] [FIXED] - Fixes regression of RCTWindowFrameDidChangeNotification not fired

Pull Request resolved: #47236

Test Plan: Demo in #47234.

Reviewed By: blakef

Differential Revision: D65058105

Pulled By: cipolleschi

fbshipit-source-id: 0e286182ed93f289cb853710e2e00801ef2d4f73

packages/react-native/Libraries/AppDelegate/RCTAppDelegate.mm

@@ -76,6 +76,7 @@ - (void)loadReactNativeWindow:(NSDictionary *)launchOptions
   self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
   UIViewController *rootViewController = [self createRootViewController];
   [self setRootView:rootView toRootViewController:rootViewController];
+  _window.windowScene.delegate = self;
   _window.rootViewController = rootViewController;
   [_window makeKeyAndVisible];
 }