Fix missing path for avatars of bots

This change fixes missing path for avatars of bots

app/models/concerns/avatarable.rb

@@ -38,7 +38,7 @@ module Avatarable
 
   class_methods do
     def bot_avatar(image:)
-      Rails.root.join('app', 'assets', 'images', 'bot_avatars', image).open
+      Rails.root.join('lib', 'assets', 'images', 'bot_avatars', image).open
     end
   end
 

changelogs/unreleased/231251-error-500-in-service-desk-due-missing-asset.yml

+---
+title: Fix missing path for avatars of bots
+merge_request: 37671
+author:
+type: fixed