Debian 11 bullseye-security repos have gone missing after botched EOL process

Debian's bullseye-security repositories have disappeared due to a flawed end-of-life process. The issue is discussed in a post on the Debian mirrors mailing list and has garnered comments on Hacker News. The problem has been noted by users, with a link to the relevant mailing list discussion and a related comments thread available. The disappearance of the repositories has been observed and reported by the community.