### Godot version

v4.0.beta17.mono.official [c40020513]

### System information

Window 11, Forward+, GTX 1060

### Issue description

Adding two theme variations in a row result to a  crash.

https://user-images.githubusercontent.com/93253123/217037249-1ce1d56d-beb6-4435-83ad-9f8a07fe0e96.mp4



### Steps to reproduce

1. Create a project.
2. Create a theme.
3. Double click to go in the theme editor.
4. Click on manage items buttons.
5. In the add type field type a name to add a type.
6. type another name to add a second type.
7. Crash.

### Minimal reproduction project

[ThemeVariationCrash.zip](https://github.com/godotengine/godot/files/10665863/ThemeVariationCrash.zip)

return selectable;
}
void EditorProperty::set_name_split_ratio(float p_ratio) {
	split_ratio = p_ratio;
}
float EditorProperty::get_name_split_ratio() const {
	return split_ratio;
}
void EditorProperty::set_object_and_property(Object *p_object, const StringName &p_property) {
	object = p_object;
	property = p_property;
	_update_pin_flags();
}
static bool _is_value_potential_override(Node *p_node, const String &p_property) {
	
	
	
	Node *edited_scene = EditorNode::get_singleton()->get_edited_scene();
	Vector<SceneState::PackState> states_stack = PropertyUtils::get_node_states_stack(p_node, edited_scene);
	if (states_stack.size()) {
		return true;
	} else {
		bool is_valid_default = false;
		bool is_class_default = false;
		PropertyUtils::get_property_default_value(p_node, p_property, &is_valid_default, &states_stack, false, nullptr, &is_class_default);
		return !is_class_default;
	}
}
void EditorProperty::_update_pin_flags() {