Merge branch 'sidekiq-setup' into 'master'

Consolidate Sidekiq instance setup details

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/156370



Merged-by: Achilleas Pipinellis <axil@gitlab.com>
Approved-by: Achilleas Pipinellis <axil@gitlab.com>
Reviewed-by: Nailia Iskhakova <niskhakova@gitlab.com>
Co-authored-by: Ben Bodenmiller <bbodenmiller@gmail.com>