The main thing here is pulling in libzstd in the nix derivation so it doesn't use the vendored version. This matches nixpkgs after https://github.com/NixOS/nixpkgs/pull/582391 so thank you again @whispers.systems for noticing this!
Figure I might as well update nixpkgs while I'm at it. And noticed the deprecated method too. Switching over to the non-deprecated version does set our MSRV to 1.95.0 which is maybe a little high but so far we haven't done anything especially to keep it low. Most major distros seem to be shipping 1.95.0 or later in their lastest stable anyways so I don't think it'll be too big an issue. Could see an argument for not doing it though.
