chore: Remove delete Instagram story implementation (#11097)

Currently, Instagram stories are downloaded and displayed as
attachments. We previously implemented story deletion by checking
individual messages via
https://github.com/chatwoot/chatwoot/pull/5300/files#diff-684a16c1b0b4c099fcdfeed95b1820e11fef629fe332ec7ce6a8c600331dd06dR110,
but this approach proved impractical and was removed. This PR removes
all unused code to avoid confusion. We will revisit the story deletion
feature when we implement `instagram_manage_insights`.

app/models/channel/facebook_page.rb

@@ -63,22 +63,4 @@ class Channel::FacebookPage < ApplicationRecord
     Rails.logger.debug { "Rescued: #{e.inspect}" }
     true
   end
-
-  # TODO: We will be removing this code after instagram_manage_insights is implemented
-  def fetch_instagram_story_link(message)
-    k = Koala::Facebook::API.new(page_access_token)
-    result = k.get_object(message.source_id, fields: %w[story]) || {}
-    story_link = result['story']['mention']['link']
-    # If the story is expired then it raises the ClientError and if the story is deleted with valid story-id it responses with nil
-    delete_instagram_story(message) if story_link.blank?
-    story_link
-  rescue Koala::Facebook::ClientError => e
-    Rails.logger.debug { "Instagram Story Expired: #{e.inspect}" }
-    delete_instagram_story(message)
-  end
-
-  def delete_instagram_story(message)
-    message.attachments.destroy_all
-    message.update(content: I18n.t('conversations.messages.instagram_deleted_story_content'), content_attributes: {})
-  end
 end

app/models/message.rb

@@ -155,15 +155,6 @@ class Message < ApplicationRecord
     }
   end
 
-  # TODO: We will be removing this code after instagram_manage_insights is implemented
-  # Better logic is to listen to webhook and remove stories proactively rather than trying
-  # a fetch every time a message is returned
-  def validate_instagram_story
-    inbox.channel.fetch_instagram_story_link(self)
-    # we want to reload the message in case the story has expired and data got removed
-    reload
-  end
-
   def merge_sender_attributes(data)
     data[:sender] = sender.push_event_data if sender && !sender.is_a?(AgentBot)
     data[:sender] = sender.push_event_data(inbox) if sender.is_a?(AgentBot)