wayland: Remove the registry from the window properties

A Wayland registry object can only have one listener attached at a time, so an application attempting to use the backend SDL registry object for its own purposes will just result in an error. Remove this property, as it is of no use to applications and will only result in errors.

If an application needs the registry, it needs to get the wl_display object via `SDL.window.wayland.display` and use wl_display_get_registry() to create a new registry object that it can attach its own listeners to.

include/SDL3/SDL_video.h

@@ -1033,8 +1033,6 @@ extern DECLSPEC SDL_Window *SDLCALL SDL_GetWindowParent(SDL_Window *window);
  * show/hide calls. They will be null if the window is hidden and must be
  * queried each time it is shown.
  *
- * - `SDL_PROPERTY_WINDOW_WAYLAND_REGISTRY_POINTER`: the wl_registry
- *   associated with the window
  * - `SDL_PROPERTY_WINDOW_WAYLAND_DISPLAY_POINTER`: the wl_display associated
  *   with the window
  * - `SDL_PROPERTY_WINDOW_WAYLAND_SURFACE_POINTER`: the wl_surface associated
@@ -1086,7 +1084,6 @@ extern DECLSPEC SDL_PropertiesID SDLCALL SDL_GetWindowProperties(SDL_Window *win
 #define SDL_PROPERTY_WINDOW_WIN32_HWND_POINTER              "SDL.window.win32.hwnd"
 #define SDL_PROPERTY_WINDOW_WIN32_HDC_POINTER               "SDL.window.win32.hdc"
 #define SDL_PROPERTY_WINDOW_WIN32_INSTANCE_POINTER          "SDL.window.win32.instance"
-#define SDL_PROPERTY_WINDOW_WAYLAND_REGISTRY_POINTER        "SDL.window.wayland.registry"
 #define SDL_PROPERTY_WINDOW_WAYLAND_DISPLAY_POINTER         "SDL.window.wayland.display"
 #define SDL_PROPERTY_WINDOW_WAYLAND_SURFACE_POINTER         "SDL.window.wayland.surface"
 #define SDL_PROPERTY_WINDOW_WAYLAND_EGL_WINDOW_POINTER      "SDL.window.wayland.egl_window"

src/video/wayland/SDL_waylandwindow.c

@@ -2154,7 +2154,6 @@ int Wayland_CreateWindow(SDL_VideoDevice *_this, SDL_Window *window, SDL_Propert
     } /* All other cases will be WAYLAND_SURFACE_UNKNOWN */
 
     SDL_PropertiesID props = SDL_GetWindowProperties(window);
-    SDL_SetProperty(props, SDL_PROPERTY_WINDOW_WAYLAND_REGISTRY_POINTER, c->registry);
     SDL_SetProperty(props, SDL_PROPERTY_WINDOW_WAYLAND_DISPLAY_POINTER, data->waylandData->display);
     SDL_SetProperty(props, SDL_PROPERTY_WINDOW_WAYLAND_SURFACE_POINTER, data->surface);
     SDL_SetProperty(props, SDL_PROPERTY_WINDOW_WAYLAND_EGL_WINDOW_POINTER, data->egl_window);