Decouple sidekiq from sidekiq-cluster
This MR add back in the changes from https://gitlab.com/gitlab-org/omnibus-gitlab/merge_requests/1660
and Fixes: https://gitlab.com/gitlab-org/omnibus-gitlab/issues/2506
I believe the prievious issue with this change was due to the chef-repo roles not being properly updated to no run init/sidekiq 1 on the sidekiq-cluster