Removes cross-joins FF in MergeRequest#environements

Changelog: changed

app/models/merge_request.rb

@@ -1409,19 +1409,15 @@ class MergeRequest < ApplicationRecord
   def environments
     return Environment.none unless actual_head_pipeline&.merge_request?
 
-    if ::Feature.enabled?(:avoid_cross_joins_environments_merge_request, default_enabled: :yaml)
-      build_for_actual_head_pipeline = Ci::Build.latest.where(pipeline: actual_head_pipeline)
+    build_for_actual_head_pipeline = Ci::Build.latest.where(pipeline: actual_head_pipeline)
 
-      environments = build_for_actual_head_pipeline.joins(:metadata)
-                                                  .where.not('ci_builds_metadata.expanded_environment_name' => nil)
-                                                  .distinct('ci_builds_metadata.expanded_environment_name')
-                                                  .limit(100)
-                                                  .pluck(:expanded_environment_name)
+    environments = build_for_actual_head_pipeline.joins(:metadata)
+                                                .where.not('ci_builds_metadata.expanded_environment_name' => nil)
+                                                .distinct('ci_builds_metadata.expanded_environment_name')
+                                                .limit(100)
+                                                .pluck(:expanded_environment_name)
 
-      Environment.where(project: project, name: environments)
-    else
-      actual_head_pipeline.environments
-    end
+    Environment.where(project: project, name: environments)
   end
 
   def fetch_ref!

config/feature_flags/development/avoid_cross_joins_environments_merge_request.yml

----
-name: avoid_cross_joins_environments_merge_request
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/71591
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/343236
-milestone: '14.5'
-type: development
-group: group::sharding
-default_enabled: false