### 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 (!root) {
		return nullptr;
	}
	while (true) {
		if (!p_item) {
			p_item = root;
		} else {
			if (p_item->first_child) {
				p_item = p_item->first_child;
			} else if (p_item->next) {
				p_item = p_item->next;
			} else {
				while (!p_item->next) {
					p_item = p_item->parent;
					if (p_item == nullptr) {
						return nullptr;
					}
				}
				p_item = p_item->next;
			}
		}
		for (int i = 0; i < columns.size(); i++) {
			if (p_item->cells[i].selected) {
				return p_item;
			}
		}
	}
	return nullptr;
}
int Tree::get_column_minimum_width(int p_column) const {