### 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
TreeItem *from = p_at;
	TreeItem *loop = nullptr; 
	while (p_at) {
		for (int i = 0; i < columns.size(); i++) {
			if (p_at->get_text(i).findn(p_find) == 0 && (!p_selectable || p_at->is_selectable(i))) {
				if (r_col) {
					*r_col = i;
				}
				return p_at;
			}
		}
		if (p_backwards) {
			p_at = p_at->get_prev_visible(true);
		} else {
			p_at = p_at->get_next_visible(true);
		}
		if ((p_at) == from) {
			break;
		}
		if (!loop) {
			loop = p_at;
		} else if (loop == p_at) {
			break;
		}
	}
	return nullptr;
}
TreeItem *Tree::search_item_text(const String &p_find, int *r_col, bool p_selectable) {