### Godot version

2992ffd25523cb8b3e0ef1b873c40115b8940178

### System information

Windows 10

### Issue description

Godot crashes randomly within a few seconds after project start when moving with the mouse.

![win_err](https://github.com/godotengine/godot/assets/52464204/1da28596-d95b-40f3-b32f-12219ec02c5d)

Started after recent merge of https://github.com/godotengine/godot/pull/67791.
I can confirm that reverting the pr fixes the crashes.

### Steps to reproduce

see desc

### Minimal reproduction project

N/A
if (!get_parent()) {
		
		return;
	}
	
	Viewport *vp = get_parent()->get_viewport();
	Window *window = nullptr;
	while (vp) {
		window = Object::cast_to<Window>(vp);
		if (window) {
			break;
		}
		if (!vp->get_parent()) {
			break;
		}
		vp = vp->get_parent()->get_viewport();
	}
	if (window) {
		transient_parent = window;
		window->transient_children.insert(this);
		if (is_inside_tree() && is_visible() && exclusive) {
			if (transient_parent->exclusive_child == nullptr) {
				if (!is_in_edited_scene_root()) {
					transient_parent->exclusive_child = this;
				}