Verify and prune CODEOWNERS list for translations

Hi code owners (@suetfei, @wnghl, @anlunx, ...), can you please take a look at this one?

@henrif75, I think we should consider pruning the list of code owners here in case some of them have moved on — this way the contributors will have a more clear picture of what to expect when creating a PR. It's a lot of work to review these PRs, so a huge thank you goes to the many volunteers here!

_Originally posted by @mgeisler in https://github.com/google/comprehensive-rust/issues/1992#issuecomment-2093010247_