power-action module: no need for stockholm/lib

this makes the module available to be reused by others without the need
for having stockholm in the search path

krebs/3modules/power-action.nix

@@ -1,7 +1,6 @@
 { config, lib, pkgs, ... }:
 
-with import <stockholm/lib>;
-
+with lib;
 let
   cfg = config.krebs.power-action;