Remove old bg migration from rubocop todo files

Removed in https://gitlab.com/gitlab-org/gitlab/-/merge_requests/92395

.rubocop_todo/database/multiple_databases.yml

@@ -7,7 +7,6 @@ Database/MultipleDatabases:
     - 'db/post_migrate/20210812013042_remove_duplicate_project_authorizations.rb'
     - 'ee/spec/services/ee/merge_requests/update_service_spec.rb'
     - 'lib/gitlab/background_migration/backfill_projects_with_coverage.rb'
-    - 'lib/gitlab/background_migration/copy_ci_builds_columns_to_security_scans.rb'
     - 'spec/db/schema_spec.rb'
     - 'spec/initializers/database_config_spec.rb'
     - 'spec/lib/gitlab/database_spec.rb'

.rubocop_todo/migration/background_migration_base_class.yml

@@ -26,7 +26,6 @@ Migration/BackgroundMigrationBaseClass:
     - 'lib/gitlab/background_migration/backfill_work_item_type_id_for_issues.rb'
     - 'lib/gitlab/background_migration/cleanup_draft_data_from_faulty_regex.rb'
     - 'lib/gitlab/background_migration/cleanup_orphaned_lfs_objects_projects.rb'
-    - 'lib/gitlab/background_migration/copy_ci_builds_columns_to_security_scans.rb'
     - 'lib/gitlab/background_migration/create_security_setting.rb'
     - 'lib/gitlab/background_migration/delete_orphaned_deployments.rb'
     - 'lib/gitlab/background_migration/disable_expiration_policies_linked_to_no_container_images.rb'

.rubocop_todo/rails/squished_sql_heredocs.yml

@@ -136,7 +136,6 @@ Rails/SquishedSQLHeredocs:
     - 'lib/gitlab/background_migration/backfill_project_settings.rb'
     - 'lib/gitlab/background_migration/backfill_projects_with_coverage.rb'
     - 'lib/gitlab/background_migration/backfill_upvotes_count_on_issues.rb'
-    - 'lib/gitlab/background_migration/copy_ci_builds_columns_to_security_scans.rb'
     - 'lib/gitlab/background_migration/disable_expiration_policies_linked_to_no_container_images.rb'
     - 'lib/gitlab/background_migration/encrypt_static_object_token.rb'
     - 'lib/gitlab/background_migration/fix_duplicate_project_name_and_path.rb'