### Godot version

v4.1.rc1.official [1f9e540f1]

### System information

Windows 10

### Issue description

Attempting to reorder the children of a TabContainer results in an unintended ordering and incorrect undo states.

Also happens in v4.0.3.stable.official [5222a99f5].

https://github.com/godotengine/godot/assets/3820082/2c2458e3-88ad-46d9-8a04-f289a049984a



### Steps to reproduce

1. Add a new TabContainer
2. Add a few children to it
3. Drag and drop to erroneously reorder them
4. Attempt to undo the change

### Minimal reproduction project

N/A
Vector<String> scenes;
	scenes.push_back(p_file);
	instantiate_scenes(scenes, scene_tree->get_selected());
}
void SceneTreeDock::instantiate_scenes(const Vector<String> &p_files, Node *p_parent) {
	Node *parent = p_parent;
	if (!parent) {
		parent = scene_tree->get_selected();
	}
	if (!parent) {
		parent = edited_scene;
	}
	if (!parent) {
		if (p_files.size() == 1) {
			accept->set_text(TTR("No parent to instantiate a child at."));
		} else {
			accept->set_text(TTR("No parent to instantiate the scenes at."));
		}
		accept->popup_centered();
		return;
	};
	_perform_instantiate_scenes(p_files, parent, -1);
}
void SceneTreeDock::_perform_instantiate_scenes(const Vector<String> &p_files, Node *parent, int p_pos) {
	ERR_FAIL_COND(!parent);
	Vector<Node *> instances;