### Godot version

4.0.3.stable

### System information

windows 11

### Issue description

fullscreen on the window node is not working and will show up as a windowed.

### Steps to reproduce

disable Embed Subwindows in Project Settings/Display/Window.
create a window node and set its mode to fullscreen.

### Minimal reproduction project

[fullscreen.zip](https://github.com/godotengine/godot/files/11821834/fullscreen.zip)
ERR_MAIN_THREAD_GUARD;
	current_screen = p_screen;
	if (window_id == DisplayServer::INVALID_WINDOW_ID) {
		return;
	}
	DisplayServer::get_singleton()->window_set_current_screen(p_screen, window_id);
}
int Window::get_current_screen() const {
	ERR_READ_THREAD_GUARD_V(0);
	if (window_id != DisplayServer::INVALID_WINDOW_ID) {
		current_screen = DisplayServer::get_singleton()->window_get_current_screen(window_id);
	}
	return current_screen;
}
void Window::set_position(const Point2i &p_position) {
	ERR_MAIN_THREAD_GUARD;
	position = p_position;
	if (embedder) {
		embedder->_sub_window_update(this);
	} else if (window_id != DisplayServer::INVALID_WINDOW_ID) {
		DisplayServer::get_singleton()->window_set_position(p_position, window_id);
	}
}
Point2i Window::get_position() const {
	ERR_READ_THREAD_GUARD_V(Point2i());
	return position;
}
void Window::set_size(const Size2i &p_size) {