We need archive the contents present on https://www.x.org/releases/
The lister has to be one shot because the packages are no longer updated and as mentioned in https://www.x.org/wiki/, there is only one directory which is updated. That is https://www.x.org/releases/individual/, as it is also mentioned
further development work is being done in conjunction with the freedesktop.org
However, the packages that are updated on https://www.x.org/releases/individual/ are also present on the Gitlab page of freedesktop.org (https://gitlab.freedesktop.org/xorg). As Gitlab lister is already present, so we can skip https://www.x.org/releases/individual/
Hence this would be one-shot.
Any API or some index file is not available for this website so the best approach would be the scrape https://www.x.org/releases/ and get the tarball links. These can directly be fed to loader-tar to ingest.