Bind the io.systemd.SysUpdate.Notify.OnCompletedUpdate() method in the
pcrlock Varlink server and hook a socket into
/run/systemd/sysupdate/notify/ via systemd-sysupdate-notify-pcrlock.socket,
enabled by default via the preset. When sysupdate signals a completed
update, we unconditionally re-run make-policy, since the set of measured
components may have changed.
