Merge branch 'osw-supervise-sidekiq-cluster-for-core' into 'master'

Run Sidekiq Cluster supervision on Core

See merge request gitlab-org/gitlab!27249

config/initializers/sidekiq_cluster.rb

 # frozen_string_literal: true
 
-if ENV['ENABLE_SIDEKIQ_CLUSTER'] && Gitlab.ee?
+if ENV['ENABLE_SIDEKIQ_CLUSTER']
   Thread.new do
     Thread.current.abort_on_exception = true