### Godot version

v4.0.beta17.mono.official [c40020513]

### System information

Window 11, Forward+, GTX 1060

### Issue description

Adding two theme variations in a row result to a  crash.

https://user-images.githubusercontent.com/93253123/217037249-1ce1d56d-beb6-4435-83ad-9f8a07fe0e96.mp4



### Steps to reproduce

1. Create a project.
2. Create a theme.
3. Double click to go in the theme editor.
4. Click on manage items buttons.
5. In the add type field type a name to add a type.
6. type another name to add a second type.
7. Crash.

### Minimal reproduction project

[ThemeVariationCrash.zip](https://github.com/godotengine/godot/files/10665863/ThemeVariationCrash.zip)

int check_ofs = get_theme_constant(SNAME("hseparator"), SNAME("Tree")) + checkbox->get_width() + get_theme_constant(SNAME("h_separation"), SNAME("CheckBox"));
				ofs += check_ofs;
				text_limit -= check_ofs;
			} else {
				check_rect = Rect2();
			}
			if (can_revert && !is_read_only()) {
				Ref<Texture2D> reload_icon = get_theme_icon(SNAME("ReloadSmall"), SNAME("EditorIcons"));
				text_limit -= reload_icon->get_width() + get_theme_constant(SNAME("hseparator"), SNAME("Tree")) * 2;
				revert_rect = Rect2(ofs + text_limit, (size.height - reload_icon->get_height()) / 2, reload_icon->get_width(), reload_icon->get_height());
				Color color2(1, 1, 1);
				if (revert_hover) {
					color2.r *= 1.2;
					color2.g *= 1.2;
					color2.b *= 1.2;
				}
				if (rtl) {
					draw_texture(reload_icon, Vector2(size.width - revert_rect.position.x - reload_icon->get_width(), revert_rect.position.y), color2);
				} else {
					draw_texture(reload_icon, revert_rect.position, color2);
				}
			} else {
				revert_rect = Rect2();
			}
			if (!pin_hidden && pinned) {
				Ref<Texture2D> pinned_icon = get_theme_icon(SNAME("Pin"), SNAME("EditorIcons"));
				int margin_w = get_theme_constant(SNAME("hseparator"), SNAME("Tree")) * 2;
				int total_icon_w = margin_w + pinned_icon->get_width();
				int text_w = font->get_string_size(label, rtl ? HORIZONTAL_ALIGNMENT_RIGHT : HORIZONTAL_ALIGNMENT_LEFT, text_limit - total_icon_w, font_size).x;
				int y = (size.height - pinned_icon->get_height()) / 2;