This file is just placeholder for creating content in /usr/bin/X/ directory.

The directory is used to trick display-manager.service (script) to think that
xorg-x11-server is installed. If the directory is not existing the above
script/service ends with error reporting status=6/NOTCONFIGURED. We want to
use Wayland (only), there is no sense in installing X11 server too. As it is
not mentioned as direct dependency in any gnome and wayland related packages
and kind of dependency happens only due to that check, we trick it by creating
the directory.

This is status at time of initial Wayland / GNOME Shell deployment in Agama's
live ISO. If the check is removed in the future feel free to drop whole
/usr/bin/X from the image.
