Audit log shows failed login attempt when joining as a moderator

[stevenGravy]

Expected behavior:

A auth attempt failed record would not show for a moderated or join session process. This does not occur in v16.

Current behavior:

If webauth is enabled on a v17 then a user is challenged to join with a MFA for a session. A audit entry of a failed auth attempt is shown

Bug details:

• Teleport version: 17.0.0 beta 1
• Recreation steps

1. Configure a Teleport v17 cluster to have webauthn enabled
2. Connect and open a ssh session
3. Connect separately as a moderator
4. Review audit log