Fix Editor Description tooltip not changing until scene is reopened

You still need to select another node to see the tooltip updated first,
but you no longer need to save and reopen the scene to view the updated
tooltip.

scene/main/node.cpp

@@ -1987,7 +1987,16 @@ String Node::get_scene_file_path() const {
 }
 
 void Node::set_editor_description(const String &p_editor_description) {
+	if (data.editor_description == p_editor_description) {
+		return;
+	}
+
 	data.editor_description = p_editor_description;
+
+	if (Engine::get_singleton()->is_editor_hint() && is_inside_tree()) {
+		// Update tree so the tooltip in the Scene tree dock is also updated in the editor.
+		get_tree()->tree_changed();
+	}
 }
 
 String Node::get_editor_description() const {