Preconcurrency Notification names in submodules

Update: This may not be a bug. While I said I was using @preconcurrency import ..., I failed to mention that there was also a previous import SwiftUI which had already imported UIKit. Rearranging to put @preconcurrency import UIKit fixes it. This is possibly an easy mistake for devs to make, so it would be really nice if "re-import, but with @preconcurrency" worked, but I don't think it's a bug. More of a "back to C include order" situation.