Merge branch 'kerrizor/remove-codeowners_match_ancestor_groups-flag' into 'master'

Remove codeowners_match_ancestor_groups feature flag

See merge request gitlab-org/gitlab!43606

ee/config/feature_flags/development/codeowners_match_ancestor_groups.yml

----
-name: codeowners_match_ancestor_groups
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/31887
-rollout_issue_url:
-group: group::source code
-type: development
-default_enabled: true

ee/lib/gitlab/code_owners/groups_loader.rb

@@ -24,7 +24,6 @@ module Gitlab
 
         groups = project.invited_groups.where_full_path_in(extractor.names)
 
-        if Feature.enabled?(:codeowners_match_ancestor_groups, default_enabled: true)
         group_list = groups.with_route.with_users.to_a
 
         if project.group
@@ -37,9 +36,6 @@ module Gitlab
         end
 
         group_list.uniq
-        else
-          groups.with_route.with_users
-        end
       end
 
       def applicable_ancestors(extractor_names)