Try to eliminate the need of patching `golang.org/x/crypto/ssh`

[stevapple]

It would be great if we don't vendor a modified copy of the library. It's a perfect time now to check which API we need doesn't exist now, and try to get them into the new golang.org/x/crypto/ssh/v2 package.

[stevapple]

@iBug 42b2075 is the only patch to existing x/crypto/ssh codebase, can you elaborate on the context? I didn't find a related issue in https://github.com/golang/go

[iBug]

The context is loosely in the commit message. For Ubuntu 22.04 and lower, the packaged openssh-server doesn't implement the new "ping" protocol, and would exit immediately upon receiving one (unknown packet type 192). We found it easier to disable this optional feature altogether in that patch.