`systemd-sysupdate.service` and `systemd-sysupdate-reboot.service` are in a failed state

[tormath1]

Description

With systemd upgrade on current Alpha / Beta (>=4515), those two units are in a failed state:

$ systemctl --failed
  UNIT                             LOAD   ACTIVE SUB    DESCRIPTION
● systemd-sysupdate-reboot.service loaded failed failed Reboot Automatically After System Update
● systemd-sysupdate.service        loaded failed failed Automatic System Update

Legend: LOAD   → Reflects whether the unit definition was properly loaded.
        ACTIVE → The high-level unit activation state, i.e. generalization of SUB.
        SUB    → The low-level unit activation state, values depend on unit type.

2 loaded units listed.

This is because the systemd-sysupdate.timer unit is enabled by default following the systemd upgrade.

Impact

This is harmless, this happens when there's no sysext image candidate for upgrade:

 systemd-sysupdate[3835]: No transfer definitions found.

[pothos]

While this was important for Beta/Alpha, it's also nice for LTS/Stable and we should backport flatcar/init#139 on an init-backport branch

[pothos]

For LTS the file still needs to be called .conf

[pothos]

Ah, same for stable, so we need a backport branch...