Change bridgeless check in dev menu (facebook#43976)

Summary:
We would set the value of  _bridge ivar to bridgeProxy for turbo module in bridgeless mode in facebook#43757 , so we need to change the way of bridgeless/bridge check.

## Changelog:

[IOS] [FIXED] - Change bridgeless check in dev menu

Pull Request resolved: facebook#43976

Test Plan: Dev menu shows bridgeless/bridge mode correctly.

Reviewed By: christophpurrer

Differential Revision: D56056640

Pulled By: cipolleschi

fbshipit-source-id: 1358c3027c1d5f12c70dd4486cc1d5975c7a185a

packages/react-native/React/CoreModules/RCTDevMenu.mm

@@ -396,7 +396,7 @@ - (void)setDefaultJSBundle
       ? UIAlertControllerStyleActionSheet
       : UIAlertControllerStyleAlert;
 
-  NSString *devMenuType = self.bridge ? @"Bridge" : @"Bridgeless";
+  NSString *devMenuType = [self.bridge isKindOfClass:RCTBridge.class] ? @"Bridge" : @"Bridgeless";
   NSString *devMenuTitle = [NSString stringWithFormat:@"React Native Dev Menu (%@)", devMenuType];
 
   _actionSheet = [UIAlertController alertControllerWithTitle:devMenuTitle message:description preferredStyle:style];