### Godot version

v4.1.1.stable.official [bd6af8e0e]

### System information

Godot v4.1.1.stable - Debian GNU/Linux trixie/sid trixie - Vulkan (Compatibility) - Mesa Intel(R) HD Graphics 520 (SKL GT2) () - Intel(R) Core(TM) i7-6500U CPU @ 2.50GHz (4 Threads)

### Issue description

After right clicking in thet "Filter Nodes" menu in the scene tree dock, the sub-menu is populated with a "Search" icon.

If I later switch themes in the same session, this icon is never updated to match the new theme.

![image](https://github.com/godotengine/godot/assets/660911/14336bb3-12ca-48c8-b030-8ada6ac27ec6)


### Steps to reproduce

1. Right click in the "Filter Nodes" menu in scene tree dock
2. Switch themes
3. Right click again in the "Filter Nodes" menu

Expected result: Icon has updated to match the theme I am currently using
Actual result: Icon is still using the theme I launched Godot with

### Minimal reproduction project

N/A
if (!_validate_no_foreign()) {
		return;
	}
	List<Node *> selection = editor_selection->get_selected_node_list();
	if (selection.is_empty()) {
		return; 
	}
	Node *to_node = get_node(p_to);
	if (!to_node) {
		return;
	}
	Vector<Node *> nodes;
	for (Node *E : selection) {
		nodes.push_back(E);
	}
	int to_pos = -1;
	_normalize_drop(to_node, to_pos, p_type);
	_do_reparent(to_node, to_pos, nodes, !Input::get_singleton()->is_key_pressed(Key::SHIFT));
}
void SceneTreeDock::_add_children_to_popup(Object *p_obj, int p_depth) {