### 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)
size.y = MAX(size.y, 1);
		embedder->_sub_window_update(this);
	} else if (window_id != DisplayServer::INVALID_WINDOW_ID) {
		if (reset_min_first && wrap_controls) {
			
			DisplayServer::get_singleton()->window_set_min_size(Size2i(), window_id);
		}
		DisplayServer::get_singleton()->window_set_max_size(max_size_used, window_id);
		DisplayServer::get_singleton()->window_set_min_size(size_limit, window_id);
		DisplayServer::get_singleton()->window_set_size(size, window_id);
	}
	
	_update_viewport_size();
}
void Window::_update_viewport_size() {
	
	Size2i final_size;
	Size2i final_size_override;
	Rect2i attach_to_screen_rect(Point2i(), size);
	float font_oversampling = 1.0;
	window_transform = Transform2D();
	if (content_scale_mode == CONTENT_SCALE_MODE_DISABLED || content_scale_size.x == 0 || content_scale_size.y == 0) {
		font_oversampling = content_scale_factor;
		final_size = size;
		final_size_override = Size2(size) / content_scale_factor;
	} else {
		
		Size2 video_mode = size;
		Size2 desired_res = content_scale_size;
		Size2 viewport_size;