Remove any processes and references to support changing SAML/SCIM identities
Now that gitlab-org/gitlab!98354 (merged) is merged and live, group owners can change SAML and SCIM identities on their own.
Support should remove/deprecate any process or references to us doing it on users' behalf.
- Internal request template: https://gitlab.com/gitlab-com/support/internal-requests/-/merge_requests/138
- Handbook: gitlab-com/www-gitlab-com!113293 (merged)