This change removes the use of the `timeout` program that previously
wrapped certain `systemctl` commands, first added in commit
144c3d022b.
`systemctl` functions as a client to the `systemd` daemon. Terminating
`systemctl` after initialization disconnects the client but does not
affect ongoing operations on the server. In practice, ending
`systemctl` only unblocked net-ssh and limited unwanted `apoptosis`
triggers.
Two recent changes render the use of `timeout` unnecessary. On the
client side, https://github.com/ubicloud/ubicloud/pull/2688 injects a
fault into the net-ssh event loop, enforcing deadlines on command
execution and handling network delays.
On the server side, commit 22f3aa5c1d
sets `logind` to terminate session processes via
`KillUserProcesses=yes`. This termination uses OpenSSH `ClientAlive`
checks to determine client liveness. If the client does not return
traffic promptly, it invokes `logind`'s session termination code.
Together, these client- and server-side changes ensure that slow or
unresponsive commands are terminated, preventing accumulation of
processes in idle sessions. All commands run under the `rhizome` user
now benefit from this, making the earlier `timeout` workaround
obsolete.