fix: .ci/gen-workflow-files.nu script

- Fix std log import (remove the asterisk)
- Add sort to dependencies field to make script output deterministic
- Remove whitespace error at EOF
- Add nushell to the default devShell, so that the script can be ran
  from the devShell

.ci/gen-workflow-files.nu

@@ -1,6 +1,6 @@
 #!/usr/bin/env nu
 
-use log *
+use std log
 
 # cd to git root
 cd (git rev-parse --show-toplevel)
@@ -116,6 +116,7 @@ for system in ($targets | columns) {
       } }
       | filter {|it| $it.needed}
       | each {|it| job-id $system $it.name}
+      | sort
     )
 
     mut new_job = {

flake.nix

@@ -319,6 +319,7 @@
               cargo-release
               clippy
               nodePackages.prettier
+              nushell # for the .ci/gen-workflow-files.nu script
               rustfmt
               packages.proverif-patched
             ];