Support installing the KCL language server through Nix/Devbox

[rrueth]

Feature Request

Is your feature request related to a problem? Please describe:
Currently, KCL itself can be installed through Nix/Devbox, but the language server cannot. Thus, if I'm setting up my own computer, or giving instructions for how to set up a KCL development environment, I need to use two different sources for KCL and the KCL language server. I'd love to be able to only use Devbox.

Describe the feature you'd like:
Allow the KCL language server to be installed through Devbox the same way that KCL can be installed.

[Peefy]

Related issue #1169

cc @He1pa

[Peefy]

https://github.com/appthrust/kcl-nix

Hello, I find the KCL language server Nix config.