Handle Sidekiq::Shutdown exception

From a slack conversation:

Should we add a list with exceptions that should not cause the counter to increase? Sidekiq::Shutdown seems like a perfect example of an error that should not stop us from retrying. And we should maybe add more like that one. Also, isn't it weird to get so many Sidekiq::Shutdown in a row? I understand a few, but could a k8s scaling event cause all those pod shutdowns? by @iroussos

Another, more recent, discussion - !168813 (comment 2174469734).