Merge branch 'russell/correct-metadata-extauth' into 'master'

Correct metadata of external auth doc

See merge request gitlab-org/gitlab!72077

doc/user/admin_area/settings/external_authorization.md

 ---
-stage: none
-group: unassigned
+stage: Manage
+group: Access
 info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
-type: reference
 ---
 
 # External authorization control **(FREE SELF)**