Enigmail's functionality has been built into Thunderbird-68, carrying
over all the way to 115. Enigmail hasn't been supported in TB since 91.
It's currently only supported on SeaMonkey, but upstream provides a
pre-packed extension to download for SM directly. Therefore there's not
much reason to package it in Gentoo, given also the current version is
years behind upstream releases. Removal in ~30 days.

-- juippis