### 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
theme_cache.select_arrow = get_theme_icon(SNAME("select_arrow"));
	theme_cache.updown = get_theme_icon(SNAME("updown"));
	theme_cache.custom_button = get_theme_stylebox(SNAME("custom_button"));
	theme_cache.custom_button_hover = get_theme_stylebox(SNAME("custom_button_hover"));
	theme_cache.custom_button_pressed = get_theme_stylebox(SNAME("custom_button_pressed"));
	theme_cache.custom_button_font_highlight = get_theme_color(SNAME("custom_button_font_highlight"));
	theme_cache.font_color = get_theme_color(SNAME("font_color"));
	theme_cache.font_selected_color = get_theme_color(SNAME("font_selected_color"));
	theme_cache.drop_position_color = get_theme_color(SNAME("drop_position_color"));
	theme_cache.h_separation = get_theme_constant(SNAME("h_separation"));
	theme_cache.v_separation = get_theme_constant(SNAME("v_separation"));
	theme_cache.inner_item_margin_bottom = get_theme_constant(SNAME("inner_item_margin_bottom"));
	theme_cache.inner_item_margin_left = get_theme_constant(SNAME("inner_item_margin_left"));
	theme_cache.inner_item_margin_right = get_theme_constant(SNAME("inner_item_margin_right"));
	theme_cache.inner_item_margin_top = get_theme_constant(SNAME("inner_item_margin_top"));
	theme_cache.item_margin = get_theme_constant(SNAME("item_margin"));
	theme_cache.button_margin = get_theme_constant(SNAME("button_margin"));
	theme_cache.icon_max_width = get_theme_constant(SNAME("icon_max_width"));
	theme_cache.font_outline_color = get_theme_color(SNAME("font_outline_color"));
	theme_cache.font_outline_size = get_theme_constant(SNAME("outline_size"));
	theme_cache.draw_guides = get_theme_constant(SNAME("draw_guides"));
	theme_cache.guide_color = get_theme_color(SNAME("guide_color"));
	theme_cache.draw_relationship_lines = get_theme_constant(SNAME("draw_relationship_lines"));
	theme_cache.relationship_line_width = get_theme_constant(SNAME("relationship_line_width"));
	theme_cache.parent_hl_line_width = get_theme_constant(SNAME("parent_hl_line_width"));
	theme_cache.children_hl_line_width = get_theme_constant(SNAME("children_hl_line_width"));
	theme_cache.parent_hl_line_margin = get_theme_constant(SNAME("parent_hl_line_margin"));
	theme_cache.relationship_line_color = get_theme_color(SNAME("relationship_line_color"));
	theme_cache.parent_hl_line_color = get_theme_color(SNAME("parent_hl_line_color"));
	theme_cache.children_hl_line_color = get_theme_color(SNAME("children_hl_line_color"));