Remove the use_distinct_in_shas_cte FF

This change removes the use_distinct_in_shas_cte feature flag.

Changelog: removed

app/finders/ci/pipelines_for_merge_request_finder.rb

@@ -47,8 +47,7 @@ module Ci
 
     # rubocop: disable CodeReuse/ActiveRecord
     def pipelines_using_cte
-      sha_relation = merge_request.all_commits.select(:sha)
-      sha_relation = sha_relation.distinct if Feature.enabled?(:use_distinct_in_shas_cte, default_enabled: :yaml)
+      sha_relation = merge_request.all_commits.select(:sha).distinct
 
       cte = Gitlab::SQL::CTE.new(:shas, sha_relation)
 

config/feature_flags/development/use_distinct_in_shas_cte.yml

----
-name: use_distinct_in_shas_cte
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/61454
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/330586
-milestone: '13.12'
-type: development
-group: group::optimize
-default_enabled: true