Bump the artifacts expire_in time to 7days for tagged builds
This will give RMs more flexibility in prepping releases ahead of time.
In general 7days likely isn't needed, but 1day (current setting) is definitely too short, and should be 2days at least. (In the case of 9.5.1 we needed to wait on a database change in production before we could continue with the deployment/release.)
This resulted in the debian 8 release not going out before the artifacts expired.
Related to: https://gitlab.com/gitlab-org/omnibus-gitlab/issues/2716
Found here: https://about.gitlab.com/2017/08/24/gitlab-9-dot-5-dot-1-released/#comment-3485452759