Move custom sshd_config to /etc/ssh/sshd_config.d/
openssh 9.4p1-2 changed /etc/ssh/sshd_config
to add support for
drop-in files in /etc/ssh/sshd_config.d/
.
Using drop-in files avoids needing to keep up with changes to the
default /etc/ssh/sshd_config
.