How can I fix this please im getting this error 'windows' was deprecated in iOS 15.0 class func topViewController(controller: UIViewController? = UIApplication.shared.windows.first?.rootViewController) -> UIViewController? {         if let navigationController = controller as? UINavigationController {             return topViewController(controller: navigationController.visibleViewController)         }         if let tabController = controller as? UITabBarController {             if let selected = tabController.selectedViewController {                 return topViewController(controller: selected)             }         }         if let presented = controller?.presentedViewController {             return topViewController(controller: presented)         }         return controller     } }