Use SDL_WindowFlags in public headers

include/SDL3/SDL_test_common.h

@@ -65,7 +65,7 @@ typedef struct
     SDL_DisplayID displayID;
     const char *window_title;
     const char *window_icon;
-    Uint32 window_flags;
+    SDL_WindowFlags window_flags;
     SDL_bool flash_on_focus_loss;
     int window_x;
     int window_y;