Instruction generator: please add Debian 11 and 12 (or remove the version entirely)

[osirisinferi]

Hi,

Just like #770, the instruction generators list of OSes is lagging behind. #770 is not fixed after almost 2 years now.

Debian 11 is already 2,5 years old and Debian 12 almost a year now.

Not having the current versions of an OS is confusing to users, as shown on the Community.

Also, I'm not sure if including "Debian Testing" is a good idea, as the stable and testing branches change regularly (in contrast to unstable, which is always called Sid).

Maybe it's a good idea to drop the differentiation between the versions entirely, as they all use the snap instructions?