add ctlptl to devshell

ctlptl can be used to create development kubernetes clusters using tools like `Kind` & `k3d`. It's a wrapper providing a common interface for these types of tools.

flake-module.nix

@@ -34,6 +34,7 @@ in
         pkgs.kubernetes-helm
         pkgs.kustomize
         pkgs.jq
+        pkgs.ctlptl
       ] ++ localFlake.withSystem system ({self', ...}: [
         self'.packages.kpt
         self'.packages.octopilot