Add alpine 3.21

[AKorezin]

Summary

Alpine release 3.21.0 on 2024-12-05. Archive.
It will be supported until 2026-11-01. Archive.

Additional

Alpine 3.21 has

• 5536 in the main repository;
• 19847 in the community repository.

for name in {main,community}; do
  count="$(curl -s "https://dl-cdn.alpinelinux.org/alpine/v3.21/$name/x86_64/APKINDEX.tar.gz" | zgrep -cP '^P:')"
  echo "$name $count";
done

Alpine edge has

• 5544 in the main repository;
• 19863 in the community repository;
• 7280 in the testing repository.

for name in {main,community,testing}; do
  count="$(curl -s "https://dl-cdn.alpinelinux.org/alpine/edge/$name/x86_64/APKINDEX.tar.gz" | zgrep -cP '^P:')"
  echo "$name $count";
done

[AKorezin]

Hello.
Did I break something because the repository was not added? Maybe I was overzealous with the minpackages parameter?

[AMDmi3]

It was not deployed yet