### Godot version

4.1 rc3

### System information

Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 (NVIDIA; 30.0.15.1403) - Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz (8 Threads)

### Issue description

This™
![image](https://github.com/godotengine/godot/assets/2223172/cb33110f-a5b0-400a-951f-3fa425f05714)

It can still happen, but it's more difficult to trigger.

### Steps to reproduce

1. Create a new scene with a Control node
2. Add Theme to the Control
3. Open Theme Editor
4. Clear the `theme` property in Control
5. Save, with Theme Editor opened
6. Restart

### Minimal reproduction project

N/A
Ref<Script> scr = Object::cast_to<Script>(p_script);
	if (scr.is_null()) {
		return;
	}
	if (p_activate_name.length()) {
		set_addon_plugin_enabled(p_activate_name, true);
	}
	project_settings_editor->update_plugins();
	project_settings_editor->hide();
	push_item(scr.operator->());
}
void EditorNode::_remove_plugin_from_enabled(const String &p_name) {