[Tails-dev] Emergency release 6.15.1

Hi!

Unsurprisingly this year's pwn2own resulted in a Firefox chemspill
release, and thus a Tor Browser release, so we'll have a Tails emergency
release as well. We're aiming to release it tomorrow, 2025-05-20.

Context:

- https://blog.torproject.org/new-release-tor-browser-1452/
- https://www.mozilla.org/en-US/security/advisories/mfsa2025-36/
-
https://blog.mozilla.org/security/2025/05/17/firefox-security-response-to-pwn2own-2025/
- https://gitlab.tails.boum.org/tails/tails/-/issues/20967

Cheers!