### 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
return drop_mode_flags;
}
void Tree::set_edit_checkbox_cell_only_when_checkbox_is_pressed(bool p_enable) {
	force_edit_checkbox_only_on_checkbox = p_enable;
}
bool Tree::get_edit_checkbox_cell_only_when_checkbox_is_pressed() const {
	return force_edit_checkbox_only_on_checkbox;
}
void Tree::set_allow_rmb_select(bool p_allow) {
	allow_rmb_select = p_allow;
}
bool Tree::get_allow_rmb_select() const {
	return allow_rmb_select;
}
void Tree::set_allow_reselect(bool p_allow) {
	allow_reselect = p_allow;
}
bool Tree::get_allow_reselect() const {
	return allow_reselect;
}
void Tree::set_allow_search(bool p_allow) {