### Godot version

Godot Engine v4.0.stable.official.92bee43ad

### System information

Windows 10

### Issue description

The documentation states that passing ```null``` into the image parameter of ```set_custom_mouse_cursor``` will change it back to the system cursor, however I find that it removes the cursor's image entirely, rather than setting it to the system's cursor.


### Steps to reproduce

```var isimage = false
var theimage = load("res://final.png")

func _on_my_button_pressed():
    if isimage == false:
        Input.set_custom_mouse_cursor(theimage, Input.CURSOR_ARROW, Vector2(16,16))
        isimage = true
        
    else:
        Input.set_custom_mouse_cursor(null)
        isimage = false```

When the button is pressed, the cursor is meant to change to the new cursor. When it has been pressed a second time, it changes back to the default cursor. However, upon pressing it a second time, it simply disappears. The cursor becomes visible again when the cursor exits and re-enters the window.

### Minimal reproduction project

[null mouse.zip](https://github.com/godotengine/godot/files/10901969/null.mouse.zip)

ERR_FAIL_COND_V_MSG(!tts, TypedArray<Dictionary>(), "Enable the \"audio/general/text_to_speech\" project setting to use text-to-speech.");
	return tts->get_voices();
}
void DisplayServerWindows::tts_speak(const String &p_text, const String &p_voice, int p_volume, float p_pitch, float p_rate, int p_utterance_id, bool p_interrupt) {
	ERR_FAIL_COND_MSG(!tts, "Enable the \"audio/general/text_to_speech\" project setting to use text-to-speech.");
	tts->speak(p_text, p_voice, p_volume, p_pitch, p_rate, p_utterance_id, p_interrupt);
}
void DisplayServerWindows::tts_pause() {
	ERR_FAIL_COND_MSG(!tts, "Enable the \"audio/general/text_to_speech\" project setting to use text-to-speech.");
	tts->pause();
}
void DisplayServerWindows::tts_resume() {
	ERR_FAIL_COND_MSG(!tts, "Enable the \"audio/general/text_to_speech\" project setting to use text-to-speech.");
	tts->resume();
}
void DisplayServerWindows::tts_stop() {
	ERR_FAIL_COND_MSG(!tts, "Enable the \"audio/general/text_to_speech\" project setting to use text-to-speech.");
	tts->stop();
}
void DisplayServerWindows::mouse_set_mode(MouseMode p_mode) {
	_THREAD_SAFE_METHOD_
	if (mouse_mode == p_mode) {
		
		return;
	}
	mouse_mode = p_mode;
	_set_mouse_mode_impl(p_mode);
}
DisplayServer::MouseMode DisplayServerWindows::mouse_get_mode() const {