### 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)
RenderingServer *rendering_server = RenderingServer::get_singleton();
	if (rendering_server) {
		max_size = rendering_server->get_maximum_viewport_size();
		max_size_used = max_size; 
	}
	theme_owner = memnew(ThemeOwner);
	RS::get_singleton()->viewport_set_update_mode(get_viewport_rid(), RS::VIEWPORT_UPDATE_DISABLED);
}
Window::~Window() {
	memdelete(theme_owner);
	
	for (KeyValue<StringName, Ref<Texture2D>> &E : theme_icon_override) {
		E.value->disconnect("changed", callable_mp(this, &Window::_notify_theme_override_changed));
	}
	for (KeyValue<StringName, Ref<StyleBox>> &E : theme_style_override) {
		E.value->disconnect("changed", callable_mp(this, &Window::_notify_theme_override_changed));
	}
	for (KeyValue<StringName, Ref<Font>> &E : theme_font_override) {
		E.value->disconnect("changed", callable_mp(this, &Window::_notify_theme_override_changed));
	}
	
	theme_icon_override.clear();
	theme_style_override.clear();
	theme_font_override.clear();
	theme_font_size_override.clear();
	theme_color_override.clear();
	theme_constant_override.clear();
}