### 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_READ_THREAD_GUARD_V(Ref<Theme>());
	return theme;
}
void Window::_theme_changed() {
	if (is_inside_tree()) {
		theme_owner->propagate_theme_changed(this, this, true, false);
	}
}
void Window::_notify_theme_override_changed() {
	if (!bulk_theme_override && is_inside_tree()) {
		notification(NOTIFICATION_THEME_CHANGED);
	}
}
void Window::_invalidate_theme_cache() {
	theme_icon_cache.clear();
	theme_style_cache.clear();
	theme_font_cache.clear();
	theme_font_size_cache.clear();
	theme_color_cache.clear();
	theme_constant_cache.clear();
}
void Window::_update_theme_item_cache() {