### Godot version

v4.0.stable.official [92bee43ad]

### System information

Linux - v4.0.stable.official [92bee43ad]

### Issue description

It gives you the possibility of removing unexisting key/value pairs from a dictionary.

### Steps to reproduce

![image](https://github.com/godotengine/godot/assets/69520693/35beadbe-bfdd-4176-9b26-222bbf69cafa)
![image](https://github.com/godotengine/godot/assets/69520693/7ed647e0-a2af-4e58-9f00-f77b7bc7bb02)
![image](https://github.com/godotengine/godot/assets/69520693/f08bf824-8408-45eb-bb84-f1dc7e19e392)


### Minimal reproduction project

N/A
switch (p_what) {
		case NOTIFICATION_THEME_CHANGED:
		case NOTIFICATION_ENTER_TREE: {
			change_type->clear();
			for (int i = 0; i < Variant::VARIANT_MAX; i++) {
				if (i == Variant::CALLABLE || i == Variant::SIGNAL || i == Variant::RID) {
					
					continue;
				}
				String type = Variant::get_type_name(Variant::Type(i));
				change_type->add_icon_item(get_theme_icon(type, SNAME("EditorIcons")), type, i);
			}
			change_type->add_separator();
			change_type->add_icon_item(get_theme_icon(SNAME("Remove"), SNAME("EditorIcons")), TTR("Remove Item"), Variant::VARIANT_MAX);
			if (button_add_item) {
				button_add_item->set_icon(get_theme_icon(SNAME("Add"), SNAME("EditorIcons")));
			}
		} break;
		case NOTIFICATION_DRAG_BEGIN: {
			if (is_visible_in_tree()) {
				if (_is_drop_valid(get_viewport()->gui_get_drag_data())) {