Closes#15196, #46918
- fix: notebook_ui, use buffer so that notebooks open in remote/WSL
settings.
- fix: add musl in nix for cross-compilation, without this remote server
doesn't build inside NixOS
Release Notes:
- Implement WSL and SSH remote kernels (crates/repl/src/kernels/*) and
wire up spawn/kill kernel proto messages and client requests.
