Hinder changing setting for sharing namespace out of hierarchy

What does this MR do and why?

Disable changing the setting for change_prevent_sharing_groups_outside_hierarchy when a namespace is effected by the free user cap.

Screenshots or screen recordings

n/a

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #349817