ssh-publickey: sign_and_send_pubkey: no mutual signature supported

[Ex-Origin]

The ssh-publickey module lacks support for rsa-sha2-256 and rsa-sha2-512, relying instead on rsa-sha. Notably, rsa-sha is deprecated in the most recent version of the OpenSSH client, resulting in connection failures.

$ ssh -V
OpenSSH_9.3p1 Ubuntu-1ubuntu3, OpenSSL 3.0.10 1 Aug 2023
$ ssh 127.0.0.1
sign_and_send_pubkey: no mutual signature supported
root@127.0.0.1: Permission denied (publickey).