Comment 5 for bug 2030684

From the 2023c-7 upload:

  * Ship only timezones in tzdata that follow the current rules of geographical
    region (continent or ocean) and city name. Move all legacy timezone symlinks
    (that are upgraded during package update) to tzdata-legacy. This includes
    dropping the special handling for US/* timezones. (Closes: #1040997)

The symlinks that were moved to tzdata-legacy come from the upstream backward file. The backward says:

# This file provides links from old or merged timezone names to current ones.
# Many names changed in 1993 and in 1995, and many merged names moved here
# in the period from 2013 through 2022. Several of these names are
# also present in the file 'backzone', which has data important only
# for pre-1970 timestamps and so is out of scope for tzdb proper.

Which of these legacy timezone names are needed for systemd except for UTC?