ESXI-67-000029 - The ESXi host must remove keys from the SSH authorized_keys file.
ESXi hosts come with SSH, which can be enabled to allow remote access without requiring user authentication. To enable password-free access, copy the remote user's public key into the '/etc/ssh/keys-root/authorized_keys' file on the ESXi host. The presence of the remote user's public key in the 'authorized_keys' file identifies the user as trusted, meaning the user is granted access to the host without providing a password. If using Lockdown Mode and SSH is disabled, then logon with authorized keys will have the same restrictions as username/password.
From an SSH session connected to the ESXi host, or from the ESXi shell, zero out or remove the /etc/ssh/keys-root/authorized_keys file: # >/etc/ssh/keys-root/authorized_keys or # rm /etc/ssh/keys-root/authorized_keys