Fix 'Authentication and Authorization' group name in doc/

What does this MR do and why?

In !77301 (merged) we renamed documentation metadata from group: Access to group: Authentication & Authorization.

As per gitlab-com/www-gitlab-com!94650 (comment 791749918), gitlab-com/www-gitlab-com!96097 (merged) we changed Authentication & Authorization to Authentication and Authorization.

This MR fixes the group name in gitlab repo.

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