### 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
ERR_FAIL_INDEX_V(p_column, cells.size(), Rect2());
	return cells[p_column].icon_region;
}
void TreeItem::set_icon_modulate(int p_column, const Color &p_modulate) {
	ERR_FAIL_INDEX(p_column, cells.size());
	if (cells[p_column].icon_color == p_modulate) {
		return;
	}
	cells.write[p_column].icon_color = p_modulate;
	_changed_notify(p_column);
}
Color TreeItem::get_icon_modulate(int p_column) const {
	ERR_FAIL_INDEX_V(p_column, cells.size(), Color());
	return cells[p_column].icon_color;
}
void TreeItem::set_icon_max_width(int p_column, int p_max) {
	ERR_FAIL_INDEX(p_column, cells.size());
	if (cells[p_column].icon_max_w == p_max) {
		return;
	}
	cells.write[p_column].icon_max_w = p_max;
	cells.write[p_column].cached_minimum_size_dirty = true;
	_changed_notify(p_column);
}
int TreeItem::get_icon_max_width(int p_column) const {