我尝试更新 Debian，但收到以下错误消息：
% sudo aptitude update
Hit http://deb.debian.org/debian bullseye InRelease
Hit http://deb.debian.org/debian-security bullseye-security InRelease
Hit http://deb.debian.org/debian bullseye-updates InRelease
Get: 1 https://cli.github.com/packages stable InRelease [3917 B]
Hit http://packages.azlux.fr/debian buster InRelease
Hit https://fasttrack.debian.net/debian-fasttrack bullseye-fasttrack InRelease
Hit https://fasttrack.debian.net/debian-fasttrack bullseye-backports-staging InRelease
Err https://cli.github.com/packages stable InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 23F3D4EA75716059
Hit https://packages.cloud.google.com/apt kubernetes-xenial InRelease
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be …