### 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;
	ERR_FAIL_COND(!p_style.is_valid());
	if (theme_style_override.has(p_name)) {
		theme_style_override[p_name]->disconnect("changed", callable_mp(this, &Window::_notify_theme_override_changed));
	}
	theme_style_override[p_name] = p_style;
	theme_style_override[p_name]->connect("changed", callable_mp(this, &Window::_notify_theme_override_changed), CONNECT_REFERENCE_COUNTED);
	_notify_theme_override_changed();
}
void Window::add_theme_font_override(const StringName &p_name, const Ref<Font> &p_font) {
	ERR_MAIN_THREAD_GUARD;
	ERR_FAIL_COND(!p_font.is_valid());
	if (theme_font_override.has(p_name)) {
		theme_font_override[p_name]->disconnect("changed", callable_mp(this, &Window::_notify_theme_override_changed));
	}
	theme_font_override[p_name] = p_font;
	theme_font_override[p_name]->connect("changed", callable_mp(this, &Window::_notify_theme_override_changed), CONNECT_REFERENCE_COUNTED);
	_notify_theme_override_changed();
}
void Window::add_theme_font_size_override(const StringName &p_name, int p_font_size) {
	ERR_MAIN_THREAD_GUARD;
	theme_font_size_override[p_name] = p_font_size;
	_notify_theme_override_changed();
}
void Window::add_theme_color_override(const StringName &p_name, const Color &p_color) {
	ERR_MAIN_THREAD_GUARD;
	theme_color_override[p_name] = p_color;
	_notify_theme_override_changed();
}
void Window::add_theme_constant_override(const StringName &p_name, int p_constant) {