Backport "Bump actions/checkout from 5 to 6" to 3.3 LTS#666

tgodzik wants to merge 1 commit intobackport-lts-3.3-24490scala/scala3-lts:backport-lts-3.3-24490from

backport-lts-3.3-24517scala/scala3-lts:backport-lts-3.3-24517Copy head branch name to clipboard