### 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)

_update_window_style(p_window, false);
	} else {
		wd.multiwindow_fs = true;
		_update_window_style(p_window, false);
	}
	if ((p_mode == WINDOW_MODE_FULLSCREEN || p_mode == WINDOW_MODE_EXCLUSIVE_FULLSCREEN) && !wd.fullscreen) {
		if (wd.minimized) {
			ShowWindow(wd.hWnd, SW_RESTORE);
		}
		wd.was_maximized = wd.maximized;
		if (wd.pre_fs_valid) {
			GetWindowRect(wd.hWnd, &wd.pre_fs_rect);
		}
		int cs = window_get_current_screen(p_window);
		Point2 pos = screen_get_position(cs) + _get_screens_origin();
		Size2 size = screen_get_size(cs);
		wd.fullscreen = true;
		wd.maximized = false;
		wd.minimized = false;
		_update_window_style(p_window, false);
		MoveWindow(wd.hWnd, pos.x, pos.y, size.width, size.height, TRUE);
		
		
		SystemParametersInfoA(SPI_GETMOUSETRAILS, 0, &restore_mouse_trails, 0);
		if (restore_mouse_trails > 1) {
			SystemParametersInfoA(SPI_SETMOUSETRAILS, 0, 0, 0);
		}
	}
}
DisplayServer::WindowMode DisplayServerWindows::window_get_mode(WindowID p_window) const {