[Tails-l10n] Release schedule for Tails 5.2

Hi,

Tails 5.2 is scheduled for 2022-06-28. boyska is the Release Manager.

tails-manual-testers@, please tell boyska how much manual QA you'll be
able to do for 5.2 (likely June 27, later afternoon CEST; and/or June
28, earlyish morning CEST).

Thanks!