### Godot version

4.2 dev1

### 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

Calling `Tree.propagate_check()` after an item is unchecked does not properly uncheck the parents. They are left in partially checked state.

It's easy to observe in theme editor:

https://github.com/godotengine/godot/assets/2223172/71d0479c-0a5e-48d3-957f-d90379a95c22



### Steps to reproduce

1. Edit a Theme resource
2. Go to Manage Items... menu
3. Go to Import Items tab
4. Unfold something
5. Check and uncheck a child checkbox

### Minimal reproduction project

N/A
return root;
}
TreeItem *Tree::get_last_item() const {
	TreeItem *last = root;
	while (last) {
		if (last->next) {
			last = last->next;
		} else if (last->first_child) {
			last = last->first_child;
		} else {
			break;
		}
	}
	return last;
}
void Tree::item_edited(int p_column, TreeItem *p_item, MouseButton p_custom_mouse_index) {
	edited_item = p_item;
	edited_col = p_column;
	if (p_item != nullptr && p_column >= 0 && p_column < p_item->cells.size()) {
		edited_item->cells.write[p_column].dirty = true;
	}
	emit_signal(SNAME("item_edited"));
	if (p_custom_mouse_index != MouseButton::NONE) {
		emit_signal(SNAME("custom_item_clicked"), p_custom_mouse_index);
	}
}
void Tree::item_changed(int p_column, TreeItem *p_item) {