"MFA failed" event is emitted every time the client checks for OIDC callback success

Existing desktop clients poll the `finish` endpoint to check if the external OIDC verification is done.
On FailedPrecondition error they retry after 5s.

On each of these failures an event is added to the activity log.
The event itself does not really represent an MFA failure, no aside from being noisy this might be misleading.