### 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 (it != drop_mode_over) {
						drop_mode_over = it;
						queue_redraw();
					}
					if (it && section != drop_mode_section) {
						drop_mode_section = section;
						queue_redraw();
					}
				}
				cache.hover_item = it;
				cache.hover_cell = col;
				if (it != old_it || col != old_col) {
					if (old_it && old_col >= old_it->cells.size()) {
						
						queue_redraw();
					} else {
						
						bool was_over_button = old_it && old_it->cells[old_col].custom_button;
						bool is_over_button = it && it->cells[col].custom_button;
						if (was_over_button || is_over_button) {
							queue_redraw();
						}
					}
				}
			}
		}
		
		if (cache.hover_type != old_hover || cache.hover_index != old_index) {
			queue_redraw();
		}