tmate inaccesible b/c no support for modern NIST ssh algos

[JoeHCQ1]

Thanks for this project, it's saved us tons of time over at Defense Unicorns GitHub.

Here is my error when I try to connect:

ssh CAVKVgmjkWuBxHfMpAPqYk5ZG@sfo2.tmate.io
Unable to negotiate with 157.230.72.130 port 22: no matching host key type found. Their offer: rsa-sha2-512,rsa-sha2-256,ssh-rsa

As far as I can tell, this is because my particular system is locked down to where it won't use any RSA - even though RSA 4096 is actually allowed - I'm gathering that with the rise of Quantum security teams are really wanting people to pivot to ECDSA (if you're trying to align with NIST) or ed25519.

If we could expand the set of host key types being offered that'd be super useful.