Option to keep latest artifact forever

Historic artifacts may be of little or no relevance. Expire works great, but I don't want latest artifat to expire ever.

It would be great if we are allowed to specify such an option, for example:

artifacts:
  paths:
    - public
  expire_in: 4 weeks 
  keep_latest: true

or for example expire_in: 4 weeks keep_latest

Another vairant would be to to devote special expiration flag only for latest:

artifacts:
  paths:
    - public
  expire_in: 4 weeks 
  expire_latest: never | 1 year