aliases/implications: remove forum topic updating code.

Remove code for updating forum topics when an alias or implication is
approved or rejected. This code was only used when approving single
alias or implication requests. This is no longer used now that all
alias/implication requests are done through BURs.

app/models/bulk_update_request.rb

@@ -67,8 +67,7 @@ class BulkUpdateRequest < ApplicationRecord
         ForumUpdater.new(
           forum_topic,
           forum_post: post,
-          expected_title: title,
-          skip_update: !TagRelationship::SUPPORT_HARD_CODED
+          expected_title: title
         )
       end
     end
@@ -88,10 +87,6 @@ class BulkUpdateRequest < ApplicationRecord
       end
     end
 
-    def date_timestamp
-      Time.now.strftime("%Y-%m-%d")
-    end
-
     def create_forum_topic
       CurrentUser.as(user) do
         self.forum_topic = ForumTopic.create(title: title, category_id: 1, creator: user) unless forum_topic.present?