kuro: replace pass with bitwarden CLI

First step to switch to bitwarden; currently hosted on ao, but haven't
finalized ao's config yet.

hosts/kuro/default.nix

@@ -56,10 +56,10 @@
       sensors.enable = true;
     };
     shell = {
+      bitwarden.enable = true;
       direnv.enable = true;
       git.enable    = true;
       gnupg.enable  = true;
-      pass.enable   = true;
       tmux.enable   = true;
       zsh.enable    = true;
     };