/username.keys endpoint requires authentication on GitLab 13.2
A question by @forfor from !35574 (comment 384561892):
@dskim_gitlab In the newest release 13.2, the https:://gitlab-instance/username.keys
endpoint requires authentication. I couldn't find any release note or issue about that. From this change it seems that it is unintentional, as there is now an explicit warning that the comment is public.
There's also #220185 (closed) respectively #34255 that touches the same API and is recently changed.
What's the intended behaviour? Is the required authentication a bug or a intended change?