Sshd *must* use PAM because we depend on it for proper session
management. The original goal of this option (disabling password
logins) can also be implemented by removing pam_auth authentication
from sshd's PAM service.
That is, you can say
security.pam.services.sshd = { options... };
instead of
security.pam.services = [ { name = "sshd"; options... } ];
making it easier to override PAM settings from other modules.
