SDL_EVENT_CLIPBOARD_UPDATE isn't sent when the primary selection changes

include/SDL3/SDL_events.h

@@ -221,7 +221,7 @@ typedef enum SDL_EventType
     /* 0x800, 0x801, and 0x802 were the Gesture events from SDL2. Do not reuse these values! sdl2-compat needs them! */
 
     /* Clipboard events */
-    SDL_EVENT_CLIPBOARD_UPDATE = 0x900, /**< The clipboard or primary selection changed */
+    SDL_EVENT_CLIPBOARD_UPDATE = 0x900, /**< The clipboard changed */
 
     /* Drag and drop events */
     SDL_EVENT_DROP_FILE        = 0x1000, /**< The system requests a file open */