Remove design_management_copy_designs feature flag

https://gitlab.com/gitlab-org/gitlab/-/issues/247062

app/services/issues/move_service.rb

@@ -63,7 +63,7 @@ module Issues
     end
 
     def queue_copy_designs
-      return unless copy_designs_enabled? && original_entity.designs.present?
+      return unless original_entity.designs.present?
 
       response = DesignManagement::CopyDesignCollection::QueueService.new(
         current_user,
@@ -74,11 +74,6 @@ module Issues
       log_error(response.message) if response.error?
     end
 
-    def copy_designs_enabled?
-      Feature.enabled?(:design_management_copy_designs, old_project) &&
-        Feature.enabled?(:design_management_copy_designs, target_project)
-    end
-
     def mark_as_moved
       original_entity.update(moved_to: new_entity)
     end

changelogs/unreleased/13426-remove-feature-flag.yml

+---
+title: Designs are moved with an Issue that is moved
+merge_request: 44524
+author:
+type: fixed

config/feature_flags/development/design_management_copy_designs.yml

----
-name: design_management_copy_designs
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/41714
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/247062
-group: group::knowledge
-type: development
-default_enabled: false
\ No newline at end of file

doc/user/project/issues/design_management.md

@@ -56,8 +56,7 @@ Support for [PDF](https://gitlab.com/gitlab-org/gitlab/issues/32811) is planned
 - From GitLab 13.1, Design filenames are limited to 255 characters.
 - Design Management data
   [isn't deleted when a project is destroyed](https://gitlab.com/gitlab-org/gitlab/-/issues/13429) yet.
-- Design Management data [won't be moved](https://gitlab.com/gitlab-org/gitlab/-/issues/13426)
-  when an issue is moved, nor [deleted](https://gitlab.com/gitlab-org/gitlab/-/issues/13427)
+- Design Management data [won't be deleted](https://gitlab.com/gitlab-org/gitlab/-/issues/13427)
   when an issue is deleted.
 - From GitLab 12.7, Design Management data [can be replicated](../../../administration/geo/replication/datatypes.md#limitations-on-replicationverification)
   by Geo but [not verified](https://gitlab.com/gitlab-org/gitlab/-/issues/32467).

spec/services/issues/move_service_spec.rb

@@ -234,14 +234,6 @@ RSpec.describe Issues::MoveService do
           subject
         end
 
-        it 'does not call QueueService when the feature flag is disabled' do
-          stub_feature_flags(design_management_copy_designs: false)
-
-          expect(DesignManagement::CopyDesignCollection::QueueService).not_to receive(:new)
-
-          subject
-        end
-
         # Perform a small integration test to ensure the services and worker
         # can correctly create designs.
         it 'copies the design and its notes', :sidekiq_inline, :aggregate_failures do