Removed spurious "extern"

src/video/uikit/SDL_uikitpen.m

@@ -134,7 +134,7 @@ static void UIKit_HandlePenAxes(SDL_Window *window, NSTimeInterval nstimestamp,
 }
 
 #if !defined(SDL_PLATFORM_TVOS)
-extern void UIKit_HandlePenHover(SDL_uikitview *view, UIHoverGestureRecognizer *recognizer)
+void UIKit_HandlePenHover(SDL_uikitview *view, UIHoverGestureRecognizer *recognizer)
 {
     float zOffset = 0.0f;
     if (@available(iOS 16.1, *)) {