Update authentication audit event to use Auditor

What does this MR do and why?

Update authentication audit event to use Auditor service

References

Ensure all audit events are using Auditor (#556329 - closed)

https://gitlab.com/gitlab-com/gl-infra/production/-/issues/20179+

Screenshots or screen recordings

BEFORE	AFTER

How to set up and validate locally

1. Simulate User Login
   1. Navigate to the login page in your local instance.
   2. Perform both standard and two-factor authentications to observe audit logging.
2. Check Audit Logs
   1. Verify that audit events are created with the correct event_name by audit event report

MR acceptance checklist

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#556329 (closed)