Remove activate service reliance on free user cap

What does this MR do and why?

Removes free user cap check on activating a member.

Free user cap no longer needs this functionality due to change in direction as seen in #371662

This was behind a feature flag as free_user_cap is turned off.

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 #371915

Related to #371662