Update doc/raketasks/cleanup.md

doc/raketasks/cleanup.md

@@ -16,6 +16,11 @@ sudo gitlab-rake gitlab:cleanup:dirs
 bundle exec rake gitlab:cleanup:dirs RAILS_ENV=production
 ```
 
+DANGER: **Danger:**
+The following task does not currently work as expected.
+The use will probably mark more existing repositories as orphaned.
+For more information, see the [issue](https://gitlab.com/gitlab-org/gitlab-ee/issues/24633).
+
 Rename repositories from all repository storage paths if they don't exist in GitLab database.
 The repositories get a `+orphaned+TIMESTAMP` suffix so that they cannot block new repositories from being created.