move initialisation of UIKit proxies to RCTHost initialisation (#49790)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/49790

changelog: [internal]

Reviewed By: cipolleschi

Differential Revision: D70399708

fbshipit-source-id: f9883616377343f6c29eaa0ccee8681967fa570c

packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTHost.mm

@@ -22,6 +22,7 @@
 #import <React/RCTPausedInDebuggerOverlayController.h>
 #import <React/RCTPerformanceLogger.h>
 #import <React/RCTReloadCommand.h>
+#import <React/RCTUtils.h>
 #import <jsinspector-modern/InspectorFlags.h>
 #import <jsinspector-modern/InspectorInterfaces.h>
 #import <jsinspector-modern/ReactCdp.h>
@@ -190,9 +191,10 @@ class RCTHostHostTargetDelegate : public facebook::react::jsinspector_modern::Ho
                                        andSetter:bundleURLSetter
                                 andDefaultGetter:defaultBundleURLGetter];
 
-    // Listen to reload commands
-    dispatch_async(dispatch_get_main_queue(), ^{
+    RCTExecuteOnMainQueue(^{
+      // Listen to reload commands
       RCTRegisterReloadCommandListener(self);
+      RCTInitializeUIKitProxies();
     });
 
     _inspectorHostDelegate = std::make_unique<RCTHostHostTargetDelegate>(self);
@@ -249,7 +251,6 @@ class RCTHostHostTargetDelegate : public facebook::react::jsinspector_modern::Ho
                                              mode:(DisplayMode)displayMode
                                 initialProperties:(NSDictionary *)properties
 {
-  RCTInitializeUIKitProxies();
   RCTFabricSurface *surface = [[RCTFabricSurface alloc] initWithSurfacePresenter:self.surfacePresenter
                                                                       moduleName:moduleName
                                                                initialProperties:properties];