In SERVER-107487, we added duration metrics for the SASL conversation that happens on the egress/client side. Currently, we test that the success log is emitted when X.509 authentication completes successfully (jstests/ssl_x509/auth_client_metrics.js).

However, there is no corresponding test for the failure case. We should add coverage to verify that the failure log — implemented in authenticate.cpp — is emitted as expected when X.509 authentication fails.