Switch to Ubuntu 22.04 for CI runner

[rabestro]

Updated the CI workflow to replace Ubuntu 20.04 with 22.04. This change improves long-term support, security, and compatibility with up-to-date tools and dependencies.

[github-actions]

Hello 👋 Thanks for your PR.

This repo does not currently have dedicated maintainers. Our cross-track maintainers team will attempt to review and merge your PR, but it will likely take longer for your PR to be reviewed.

If you enjoy contributing to Exercism and have a track-record of doing so successfully, you might like to become an Exercism maintainer for this track.

Please feel free to ask any questions, or chat to us about anything to do with this PR or the reviewing process on the Exercism forum.

(cc @exercism/cross-track-maintainers)

[IsaacG]

I'm not sure why the bot says Scala doesn't have maintainers and pings the cross-track maintainers. Github says Scala has two maintainers who should be able to handle this "internally".

[BNAndras]

Until recently, the only maintainer was Grzegorz so the repo was correctly tagged as maintained-solitary. When rabestro was added to the team, I suspect Erik or Jeremy didn't update the tag to maintained. I'll bring that up on the forums.

[ErikSchierboom]

We have to manually run the script to update the tags, but last I ran it, there was something weird going on.

[rabestro]

@IsaacG @BNAndras we are members of team Scala. We don't have a maintainer role.