Limit updating `can_create_group` and `projects_limit` via SAML to Enterprise Users

Proposal

Limit to Enterprise Users:

• Update can_create_group and projects_limit via SAML: https://docs.gitlab.com/ee/user/group/saml_sso/index.html#supported-user-attributes

Related MR that originally introduced the feature: !49394 (merged) and !72792 (merged)

Note: Adding security label since this is follow up work to &11886 (closed) and see #412898 (comment 1676197704) for documentation updates after this change