### Godot version

4.1 beta2

### System information

Windows 10 Home

### Issue description

I had a control with a custom theme which i removed. When loading the project again the Theme Editor is opened and some actions, like Show Default or Override All, cause the editor to crash.

### Steps to reproduce

1. create a scene with a Control node
2. add a custom theme to it
3. click the theme so the Theme Editor opens
4. remove the theme
5. save the scene
6. close the project and open it again (Theme Editor needs to be opened when closing the project)
7. click Show Default or Override All

### Minimal reproduction project

[Godot41_themeEditorCrash.zip](https://github.com/godotengine/godot/files/11760454/Godot41_themeEditorCrash.zip)

return plugins_list;
	}
	void make_visible(bool p_visible);
	void edit(Object *p_object);
	bool forward_gui_input(const Ref<InputEvent> &p_event);
	void forward_canvas_draw_over_viewport(Control *p_overlay);
	void forward_canvas_force_draw_over_viewport(Control *p_overlay);
	EditorPlugin::AfterGUIInput forward_3d_gui_input(Camera3D *p_camera, const Ref<InputEvent> &p_event, bool serve_when_force_input_enabled);
	void forward_3d_draw_over_viewport(Control *p_overlay);
	void forward_3d_force_draw_over_viewport(Control *p_overlay);
	void add_plugin(EditorPlugin *p_plugin);
	void remove_plugin(EditorPlugin *p_plugin);
	void clear();
	bool is_empty();
	EditorPluginList();
	~EditorPluginList();
};
struct EditorProgressBG {
	String task;
	void step(int p_step = -1) { EditorNode::progress_task_step_bg(task, p_step); }
	EditorProgressBG(const String &p_task, const String &p_label, int p_amount) {
		EditorNode::progress_add_task_bg(p_task, p_label, p_amount);
		task = p_task;
	}
	~EditorProgressBG() { EditorNode::progress_end_task_bg(task); }
};
#endif