refactor(wpcarro/emacs): Remove struct.el dep on s.el

This removes *all* of `struct.el`'s dependencies, which is liberating.

Change-Id: Ic4a2438714ecf547ba5e07a1f0e77d743941073c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6029
Tested-by: BuildkiteCI
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>

users/wpcarro/emacs/pkgs/struct/default.nix

@@ -7,10 +7,7 @@ let
         pname = "struct";
         version = "1.0.0";
         src = ./struct.el;
-        packageRequires =
-          (with emacsPackages; [
-            s
-          ]);
+        packageRequires = [ ];
       })
     { };