chore: Apply fixes for items in rubocop_todo [CW-1806] (#8864)

This PR addresses several items listed in our rubocop_todo by implementing the necessary corrections and enhancements. As a result, we are now able to remove the rubocop_todo file entirely, streamlining our codebase and ensuring adherence to our coding standards.

fixes: https://linear.app/chatwoot/issue/CW-1806/chore-rubocop-audit

app/models/account.rb

@@ -100,7 +100,7 @@ class Account < ApplicationRecord
                              .where(context: 'labels',
                                     taggable_type: 'Conversation',
                                     taggable_id: conversation_ids)
-                             .map { |_| _.tag.name }
+                             .map { |tagging| tagging.tag.name }
   end
 
   def webhook_data