Merge branch 'has-parent-fix' into 'master'

Revert has_parent? optimization

Closes #36938

See merge request gitlab-org/gitlab!27668

app/models/namespace.rb

@@ -274,7 +274,7 @@ class Namespace < ApplicationRecord
   end
 
   def has_parent?
-    parent_id.present? || parent.present?
+    parent.present?
   end
 
   def root_ancestor