Avoid including the MarkupHelper

app/helpers/markup_helper.rb

@@ -241,4 +241,6 @@ module MarkupHelper
     Banzai.post_process(html, context)
   end
+
+  extend self
 end

app/models/repository.rb

 require 'securerandom'
 class Repository
-  include MarkupHelper
   include Gitlab::ShellAdapter
   include RepositoryMirroring
@@ -530,7 +529,7 @@ class Repository
   end
   def rendered_readme
-    markup_unsafe(readme.name, readme.data, project: project) if readme
+    MarkupHelper.markup_unsafe(readme.name, readme.data, project: project) if readme
   end
   cache_method :rendered_readme