### 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
emit_signal(SNAME("item_activated"));
				incr_search.clear();
			}
		}
		accept_event();
	} else if (p_event->is_action("ui_select", true) && p_event->is_pressed()) {
		if (select_mode == SELECT_MULTI) {
			if (!selected_item) {
				return;
			}
			if (selected_item->is_selected(selected_col)) {
				selected_item->deselect(selected_col);
				emit_signal(SNAME("multi_selected"), selected_item, selected_col, false);
			} else if (selected_item->is_selectable(selected_col)) {
				selected_item->select(selected_col);
				emit_signal(SNAME("multi_selected"), selected_item, selected_col, true);
			}
		}
		accept_event();
	}
	if (allow_search && k.is_valid()) { 
		if (!k->is_pressed()) {
			return;
		}
		if (k->is_command_or_control_pressed() || (k->is_shift_pressed() && k->get_unicode() == 0) || k->is_meta_pressed()) {
			return;
		}
		if (!root) {
			return;
		}