Revert "Allow custom bot types"

This reverts custom bot type.

ee/app/models/ee/user_bot_type_enums.rb

@@ -10,9 +10,10 @@ module EE
       override :bots
       def bots
         # When adding a new key, please ensure you are not redefining a key that already exists in app/models/user_bot_type_enums.rb
-        bots_hash = super.merge(support_bot: 1, visual_review_bot: 3)
-        bots_hash[:custom] = 99 if ::Gitlab.com?
-        bots_hash
+        super.merge(
+          support_bot: 1,
+          visual_review_bot: 3
+        )
       end
     end
   end

ee/lib/analytics/merge_request_metrics_calculator.rb

@@ -19,9 +19,7 @@ module Analytics
 
     # rubocop: disable CodeReuse/ActiveRecord
     def first_comment_at
-      merge_request.related_notes.by_humans
-        .where.not(author_id: merge_request.author_id)
-        .fresh.first&.created_at
+      merge_request.related_notes.by_humans.where.not(author_id: merge_request.author_id).fresh.first&.created_at
     end
     # rubocop: enable CodeReuse/ActiveRecord