No longer compiles on visionOS

[clindsay3]

Recent versions of the visionOS beta have changed the behavior of #if os(iOS) to no longer return true on visionOS. Previous versions of the visionOS beta returned true to this. With this change, DeviceKit is once again not compiling on visionOS.

[MashfiqueA]

Support for visionOS would be a great enhancement. Eagerly awaiting this update!

[gabors]

@Zandor300 Please add enough support so we can compile on visionOS for now, actual features can come later.