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/channel/facebook_page.rb

@@ -46,20 +46,20 @@ class Channel::FacebookPage < ApplicationRecord
 
   def subscribe
     # ref https://developers.facebook.com/docs/messenger-platform/reference/webhook-events
-    response = Facebook::Messenger::Subscriptions.subscribe(
+    Facebook::Messenger::Subscriptions.subscribe(
       access_token: page_access_token,
       subscribed_fields: %w[
         messages message_deliveries message_echoes message_reads standby messaging_handovers
       ]
     )
-  rescue => e
+  rescue StandardError => e
     Rails.logger.debug { "Rescued: #{e.inspect}" }
     true
   end
 
   def unsubscribe
     Facebook::Messenger::Subscriptions.unsubscribe(access_token: page_access_token)
-  rescue => e
+  rescue StandardError => e
     Rails.logger.debug { "Rescued: #{e.inspect}" }
     true
   end
@@ -73,6 +73,7 @@ class Channel::FacebookPage < ApplicationRecord
     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