SSHd user certificate support in a 2.15.1 version

[calderonth]

Description

Hi there,

Would it be possible to release a 2.15.1 version that incorporates some of the recent SSH user/host certificates improvements?
Some of the changes to Mina SSHD to better support SSH user certificates on the server side didn't make the cut with 2.15.0.
I'm successfully using the SNAPSHOT version to test functionality but obviously would prefer using a stable version.

Motivation

SSH user certificates are massively useful in enterprise environment, we are planning on using them within Gerrit to avoid the need to inject use SSH pubkey and have a zero-touch configuration.

Alternatives considered

No response

Additional context

No response