chore: Ensure template_sync timestamp is updated (#7265)

Fix for the cases where there are multiple channels with invalid provider config, which results in the templates sync scheduler failing to schedule jobs for valid channels.

fixes: https://linear.app/chatwoot/issue/CW-2032/bug-whatsapp-template-sync-failing-in-cloud

app/models/channel/whatsapp.rb

@@ -50,6 +50,12 @@ class Channel::Whatsapp < ApplicationRecord
     true
   end
 
+  def mark_message_templates_updated
+    # rubocop:disable Rails/SkipsModelValidations
+    update_column(:message_templates_last_updated, Time.zone.now)
+    # rubocop:enable Rails/SkipsModelValidations
+  end
+
   delegate :send_message, to: :provider_service
   delegate :send_template, to: :provider_service
   delegate :sync_templates, to: :provider_service