fix: Automatically remove expired story mention (#5300)

When a user mentions the connected Instagram page in a story, the story's content is downloaded in Chatwoot, then if the user deletes the story, the content persists in the platform.

fixes: #5258

spec/jobs/webhooks/instagram_events_job_spec.rb

@@ -113,6 +113,9 @@ describe Webhooks::InstagramEventsJob do
 
         expect(instagram_inbox.messages.count).to be 1
         expect(instagram_inbox.messages.last.attachments.count).to be 1
+
+        attachment = instagram_inbox.messages.last.attachments.last
+        expect(attachment.push_event_data[:data_url]).to eq(attachment.external_url)
       end
 
       it 'creates does not create contact or messages' do