[Tails-l10n] Release schedule for Tails 5.16

Hi,

intrigeri will be the RM for Tails 5.16

The current plan is:
- **Sunday**, August 6: build images, start testing
- Monday, August 7: releasing

@testers, please let us know how much time you'll have for manual QA
from Sunday 17:00 to Monday 11:00 (Europe/Berlin)

--
boyska