### 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;
	theme_font_size_override.erase(p_name);
	_notify_theme_override_changed();
}
void Window::remove_theme_color_override(const StringName &p_name) {
	ERR_MAIN_THREAD_GUARD;
	theme_color_override.erase(p_name);
	_notify_theme_override_changed();
}
void Window::remove_theme_constant_override(const StringName &p_name) {
	ERR_MAIN_THREAD_GUARD;
	theme_constant_override.erase(p_name);
	_notify_theme_override_changed();
}
bool Window::has_theme_icon_override(const StringName &p_name) const {
	ERR_READ_THREAD_GUARD_V(false);
	const Ref<Texture2D> *tex = theme_icon_override.getptr(p_name);
	return tex != nullptr;
}
bool Window::has_theme_stylebox_override(const StringName &p_name) const {
	ERR_READ_THREAD_GUARD_V(false);
	const Ref<StyleBox> *style = theme_style_override.getptr(p_name);
	return style != nullptr;
}
bool Window::has_theme_font_override(const StringName &p_name) const {