Comment 2 for bug 2023001

Did this happen before or after you rebooted into Ubuntu 23.04?

If before the reboot, /run/sshd should already have been present on the system, created by the previous version of /lib/systemd/system/ssh.service.

If after the reboot, it should be created by /usr/lib/tmpfiles.d/openssh-server.conf, via /lib/systemd/system/systemd-tmpfiles-setup.service.

/lib/systemd/system/systemd-tmpfiles-setup.service is a dependency of sysinit.target, so this directory should be created on boot before the ssh socket connection starts up.

So I don't see why this directory would be missing for you.