How to disable the device rotation animation in SwiftUI?

We can do this almost in the same way - create a helper view controller with animation blocker and use it inside background as representable.

Tested with Xcode 13.4 / iOS 15.5

struct HelperView: UIViewControllerRepresentable {
    func makeUIViewController(context: Context) -> some UIViewController {
        OrientationHandler()
    }

    func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
    }

    class OrientationHandler: UIViewController {
        override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
            coordinator.animate(alongsideTransition: nil) { _ in
                UIView.setAnimationsEnabled(true)
            }
            UIView.setAnimationsEnabled(false)
            super.viewWillTransition(to: size, with: coordinator);
        }
    }
}

and usage:

    WindowGroup {
        ContentView()
          .background(HelperView())   // << here !!
    }

Module on GitHub