Fix perspective button hide when it should be actually disabled

(cherry picked from commit 2e5b6b5bde1e788ebe4a49e142e391937df2f3b2)

editor/plugins/spatial_editor_plugin.cpp

@@ -3010,7 +3010,7 @@ void SpatialEditorViewport::set_state(const Dictionary &p_state) {
 			previewing = Object::cast_to<Camera>(pv);
 			previewing->connect("tree_exiting", this, "_preview_exited_scene");
 			VS::get_singleton()->viewport_attach_camera(viewport->get_viewport_rid(), previewing->get_camera()); //replace
-			view_menu->hide();
+			view_menu->set_disabled(true);
 			surface->update();
 			preview_camera->set_pressed(true);
 			preview_camera->show();