Tracking issue: drop Python 2 from our repositories

Alpine Linux is removing Python 2 atm to have it gone completely by 3.11, and since Python 2 is EOL January next year, we should too.

MR's removing Python 2 dependencies: !606 (merged), !604 (merged)

Packages that so far can't be build without Python 2:

• device/linux-asus-z00vd
• kde/telepathy-logger-qt
• temp/mesa-grate
• temp/u-boot-librem5dev
• main/unicsy-demo
• main/telepathy-mission-control

These packages have to be resolved before Python 2 is dropped, as we can't just keep the package around in our tree.

For linux-asus-z00vd, mesa-grate and unicsy-demo I personally would just drop them by that time if they don't work with Python 3 yet. I doubt linux-asus-z00vd is being used by a lot of people, mesa-grate seems dead upstream and is a way outdated Mesa anyway, and unicsy-demo also seems unmaintained. Besides, I haven't heard from Pavel for a long time so I doubt the issues there will get resolved.

u-boot-librem5dev is being updated by @craftyguy currently so hopefully we can get rid of Python 2 there soon.

The Telepathy packages are being worked on upstream, and another Telepathy package has already been updated with Python 3, so I'm sure that'll happen soon here as well.