Prevent current user from blocking themselves in (the new) abuse reports

What does this MR do and why?

• Resolves the 2nd sub-task of https://gitlab.com/gitlab-org/modelops/anti-abuse/team-tasks/-/issues/185
• If an admin has been reported for abuse, they should not be allowed to take action on that report other than to just close the report. They can continue to block/report other admins.
• This MR addresses the new abuse report dashboard we have been working on which is behind a feature flag. The change has already been applied to the old abuse report dashboard, !119002 (merged)

Screenshots or screen recordings

Before	After
abuse-report-actions-before	abuse-report-actions-after

How to set up and validate locally

1. Enable feature flag abuse_reports_list
2. Log-in as any user that is not root.
3. Go to the admin profile, http://127.0.0.1:3000/root and report the user for abuse.
4. Log back in as root and navigate to the abuse reports, http://127.0.0.1:3000/admin/abuse_reports.
5. Open the abuse report, you should not be able to block/ban/delete yourself as an admin.

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.