wayland: Don't set libdecor frame visibility before the first commit

This will be needed later, after libdecor passes through toplevel bounds, but for now it causes a crash in the Cairo plugin, so remove it.

src/video/wayland/SDL_waylandwindow.c

@@ -1838,7 +1838,6 @@ void Wayland_ShowWindow(SDL_VideoDevice *_this, SDL_Window *window)
         } else {
             libdecor_frame_set_app_id(data->shell_surface.libdecor.frame, data->app_id);
             libdecor_frame_map(data->shell_surface.libdecor.frame);
-            libdecor_frame_set_visibility(data->shell_surface.libdecor.frame, !(window->flags & SDL_WINDOW_BORDERLESS));
 
             if (c->zxdg_exporter_v2) {
                 data->exported = zxdg_exporter_v2_export_toplevel(c->zxdg_exporter_v2, data->surface);