Fix Performance/MapCompact cop (#24797)

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

.rubocop_todo.yml

@@ -236,25 +236,6 @@ Naming/VariableNumber:
     - 'spec/models/user_spec.rb'
     - 'spec/services/activitypub/fetch_featured_collection_service_spec.rb'
 
-# This cop supports unsafe autocorrection (--autocorrect-all).
-Performance/MapCompact:
-  Exclude:
-    - 'app/lib/admin/metrics/dimension.rb'
-    - 'app/lib/admin/metrics/measure.rb'
-    - 'app/lib/feed_manager.rb'
-    - 'app/models/account.rb'
-    - 'app/models/account_statuses_cleanup_policy.rb'
-    - 'app/models/account_suggestions/setting_source.rb'
-    - 'app/models/account_suggestions/source.rb'
-    - 'app/models/follow_recommendation_filter.rb'
-    - 'app/models/notification.rb'
-    - 'app/models/user_role.rb'
-    - 'app/models/webhook.rb'
-    - 'app/services/process_mentions_service.rb'
-    - 'app/validators/existing_username_validator.rb'
-    - 'db/migrate/20200407202420_migrate_unavailable_inboxes.rb'
-    - 'spec/presenters/status_relationships_presenter_spec.rb'
-
 # This cop supports unsafe autocorrection (--autocorrect-all).
 Performance/UnfreezeString:
   Exclude: