### 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
if (p_item != nullptr && p_column >= 0 && p_column < p_item->cells.size()) {
		p_item->cells.write[p_column].dirty = true;
	}
	queue_redraw();
}
void Tree::item_selected(int p_column, TreeItem *p_item) {
	if (select_mode == SELECT_MULTI) {
		if (!p_item->cells[p_column].selectable) {
			return;
		}
		p_item->cells.write[p_column].selected = true;
		
		selected_col = p_column;
		selected_item = p_item;
	} else {
		select_single_item(p_item, root, p_column);
	}
	queue_redraw();
}
void Tree::item_deselected(int p_column, TreeItem *p_item) {