### 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
hbox->add_child(prop);
			prop->set_h_size_flags(SIZE_EXPAND_FILL);
			Button *edit_btn = memnew(Button);
			edit_btn->set_icon(get_theme_icon(SNAME("Edit"), SNAME("EditorIcons")));
			edit_btn->set_disabled(is_read_only());
			hbox->add_child(edit_btn);
			edit_btn->connect("pressed", callable_mp(this, &EditorPropertyDictionary::_change_type).bind(edit_btn, change_index));
			prop->update_property();
			if (i == amount + 1) {
				button_add_item = EditorInspector::create_inspector_action_button(TTR("Add Key/Value Pair"));
				button_add_item->set_icon(get_theme_icon(SNAME("Add"), SNAME("EditorIcons")));
				button_add_item->set_disabled(is_read_only());
				button_add_item->connect("pressed", callable_mp(this, &EditorPropertyDictionary::_add_key_value));
				add_vbox->add_child(button_add_item);
			}
		}
		updating = false;
	} else {
		if (container) {
			set_bottom_editor(nullptr);
			memdelete(container);
			button_add_item = nullptr;
			container = nullptr;
		}
	}
}
void EditorPropertyDictionary::_object_id_selected(const StringName &p_property, ObjectID p_id) {
	emit_signal(SNAME("object_id_selected"), p_property, p_id);
}
void EditorPropertyDictionary::_notification(int p_what) {