### 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 *prev_item = this->_get_prev_in_tree(p_wrap, true);
	return prev_item;
}
TreeItem *TreeItem::get_next_in_tree(bool p_wrap) {
	TreeItem *next_item = this->_get_next_in_tree(p_wrap, true);
	return next_item;
}
TreeItem *TreeItem::get_child(int p_index) {
	_create_children_cache();
	if (p_index < 0) {
		p_index += children_cache.size();
	}
	ERR_FAIL_INDEX_V(p_index, children_cache.size(), nullptr);
	return children_cache.get(p_index);
}
int TreeItem::get_visible_child_count() {
	_create_children_cache();
	int visible_count = 0;
	for (int i = 0; i < children_cache.size(); i++) {
		if (children_cache[i]->is_visible()) {
			visible_count += 1;
		}
	}
	return visible_count;
}
int TreeItem::get_child_count() {
	_create_children_cache();
	return children_cache.size();
}
TypedArray<TreeItem> TreeItem::get_children() {