chore: cleanup arc migration helpers (#39606)

shell/browser/ui/cocoa/electron_menu_controller.h

@@ -11,10 +11,6 @@
 #include "base/functional/callback.h"
 #include "base/memory/weak_ptr.h"
 
-#if !defined(__has_feature) || !__has_feature(objc_arc)
-#error "This file requires ARC support."
-#endif
-
 namespace electron {
 class ElectronMenuModel;
 }