Removed unused SDL_OSEvent

include/SDL3/SDL_events.h

@@ -559,15 +559,6 @@ typedef struct SDL_QuitEvent
     Uint64 timestamp;   /**< In nanoseconds, populated using SDL_GetTicksNS() */
 } SDL_QuitEvent;
 
-/**
- *  OS Specific event
- */
-typedef struct SDL_OSEvent
-{
-    Uint32 type;        /**< ::SDL_EVENT_QUIT */
-    Uint64 timestamp;   /**< In nanoseconds, populated using SDL_GetTicksNS() */
-} SDL_OSEvent;
-
 /**
  *  A user-defined event type (event.user.*)
  */