### 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 *current = get_parent();
	if (!current) {
		return;
	}
	bool all_unchecked_and_not_indeterminate = true;
	bool any_unchecked_or_indeterminate = false;
	TreeItem *child_item = current->get_first_child();
	while (child_item) {
		if (!child_item->is_checked(p_column)) {
			any_unchecked_or_indeterminate = true;
			if (child_item->is_indeterminate(p_column)) {
				all_unchecked_and_not_indeterminate = false;
				break;
			}
		} else {
			all_unchecked_and_not_indeterminate = false;
		}
		child_item = child_item->get_next();
	}
	if (all_unchecked_and_not_indeterminate) {
		current->set_checked(p_column, false);
	} else if (any_unchecked_or_indeterminate) {
		current->set_indeterminate(p_column, true);
	} else {
		current->set_checked(p_column, true);
	}