### Tested versions

- Reproducible in: v4.2.stable.arch_linux
- Not Reproducible in: v4.1.3.stable.official [f06b6836a]

### System information

Garuda Linux (2.6.19-2)

### Issue description

A minor issue where UI Icons are not rendering on the Group Editor window, attaching a screenshot for reference:
![Screenshot_604](https://github.com/godotengine/godot/assets/22623256/c366164a-3d9a-4dcf-97a0-199b5a5a7ecc)

The icons were expected for Buttons like Add, Remove, Filter, etc.

### Steps to reproduce

Select any Node and go to the `Node` panel, click `Manage Groups` and the window will open.

### Minimal reproduction project (MRP)

Minor issue, easily reproducible following the above steps.
set_min_size(Size2(600, 400) * EDSCALE);
	scene_tree = SceneTree::get_singleton();
	VBoxContainer *vbc = memnew(VBoxContainer);
	add_child(vbc);
	vbc->set_anchors_and_offsets_preset(Control::PRESET_FULL_RECT, Control::PRESET_MODE_KEEP_SIZE, 8 * EDSCALE);
	HBoxContainer *hbc = memnew(HBoxContainer);
	vbc->add_child(hbc);
	hbc->set_v_size_flags(Control::SIZE_EXPAND_FILL);
	VBoxContainer *vbc_left = memnew(VBoxContainer);
	hbc->add_child(vbc_left);
	vbc_left->set_h_size_flags(Control::SIZE_EXPAND_FILL);
	Label *group_title = memnew(Label);
	group_title->set_theme_type_variation("HeaderSmall");
	group_title->set_text(TTR("Groups"));
	vbc_left->add_child(group_title);
	groups = memnew(Tree);
	vbc_left->add_child(groups);
	groups->set_hide_root(true);
	groups->set_select_mode(Tree::SELECT_SINGLE);
	groups->set_allow_reselect(true);
	groups->set_allow_rmb_select(true);
	groups->set_v_size_flags(Control::SIZE_EXPAND_FILL);
	groups->add_theme_constant_override("draw_guides", 1);
	groups->connect("item_selected", callable_mp(this, &GroupDialog::_group_selected));
	groups->connect("button_clicked", callable_mp(this, &GroupDialog::_modify_group_pressed));