[Bug 1669607] sssd: sssd-kcm does not appear to expire Kerberos tickets

https://bugzilla.redhat.com/show_bug.cgi?id=1669607

--- Comment #11 from Florian Weimer  ---
(In reply to Pavel Březina from comment #10)
> This seems to be corresponding upstream ticket:
> https://github.com/SSSD/sssd/issues/3593

It's perhaps related, but slightly different. Expired tickets are only useful
to attackers, so there's absolutely no reason to keep them around. Purging
tickets on session end might impact some workflows negatively.