ESR91 toolchain updates

[Carsten Schoenert]

Hello Emilio,

Am 18.12.21 um 12:48 schrieb Emilio Pozuelo Monfort:
...
> Carsten, I haven't tested a thunderbird build just yet, I will do so soon, but
> if all goes well, bullseye and buster should only need some build-dep changes
> like with firefox. stretch is more complicated for both TB and FF due to the
> lack of python3.6.

I'm mostly in the final preparations for the annual X-Mas trip to my 
parents so I can due some Thunderbird work just with some delay.

I've prepared yesterday a new upload of 91.4.1 to unstable, I'm 
currently waiting on the MFSA to get the final peaces for d/changelog. 
Should hopefully happen later today so the upload should also be 
possible today.

Once this is out the door I'd start to do the merging 91.x into branch 
debian/bullseye and adjust the build-deps. Will nudge you if I'm getting 
out of time or resources to get this done soon enough.


-- 
Regards
Carsten