use list<any> for _nix_your_shell args

[michaelBelsanti]

Currently, running nix with any value Nushell doesn't parse as a string, such as an integer, float, or boolean, will cause an error, because _nix_your_shell expects only a list of strings.

Error: nu::shell::cant_convert

  × Can't convert to list<string>.
    ╭─[/nix/store/g6kcdm7nshmpljh6cfg6nrmkfs178hwj-nix-your-shell-nushell-config.nu:18:23]
 17 │ def --wrapped nix (...args) {
 18 │   _nix_your_shell nix $args
    ·                       ──┬──
    ·                         ╰── can't convert list<any> to list<string>
 19 │ }
    ╰────