DEV: Fix Lint/DuplicateMethods (#24746)

plugins/chat/app/serializers/chat/user_message_bookmark_serializer.rb

@@ -2,8 +2,6 @@
 
 module Chat
   class UserMessageBookmarkSerializer < UserBookmarkBaseSerializer
-    attr_reader :chat_message
-
     def title
       fancy_title
     end

plugins/chat/spec/system/page_objects/chat/components/messages.rb

@@ -16,10 +16,6 @@ module PageObjects
           page.find(context)
         end
 
-        def flag(message)
-          find(message).secondary_action("flag")
-        end
-
         def copy_link(message)
           find(message).secondary_action("copyLink")
         end

plugins/chat/spec/system/page_objects/chat/components/thread_list.rb

@@ -43,10 +43,6 @@ module PageObjects
           ".chat-thread-list-item__last-reply-timestamp .relative-date[data-time='#{(last_reply.created_at.iso8601.to_time.to_f * 1000).to_i}']"
         end
 
-        def has_no_unread_item?(id)
-          component.has_no_css?(item_by_id_selector(id) + ".-is-unread")
-        end
-
         def has_unread_item?(id, count: nil)
           if count.nil?
             component.has_css?(item_by_id_selector(id) + ".-is-unread")

plugins/chat/spec/system/page_objects/sidebar/sidebar.rb

@@ -14,10 +14,6 @@ module PageObjects
         find(PUBLIC_CHANNELS_SECTION_SELECTOR)
       end
 
-      def channels_section
-        find(PUBLIC_CHANNELS_SECTION_SELECTOR)
-      end
-
       def dms_section
         find(DM_CHANNELS_SECTION_SELECTOR)
       end