### 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 (!is_inside_tree()) {
		return;
	}
	if (!selected_item || (selected_col == -1)) {
		return; 
	}
	
	const Size2 area_size = _get_content_rect().size;
	int y_offset = get_item_offset(selected_item);
	if (y_offset != -1) {
		const int tbh = _get_title_button_height();
		y_offset -= tbh;