Add PATH setup back

Actually I realized this is necessary. Because I'm testing this out on
an arch system that has emacs installed at the system level it was
building doom using the system emacs instead of the nix emacs

home.nix

@@ -89,7 +89,10 @@ with import <nixpkgs> {};
     };
   };
 
-  home.activation.doomSync = lib.hm.dag.entryAfter [ "writeBoundary" ] (''
+  home.activation.doomSync = lib.hm.dag.entryAfter [ "writeBoundary" ] (let
+    emacs = pkgs.emacs;
+  in ''
+    export PATH=${emacs}/bin:$PATH
     ${config.xdg.configHome}/emacs/bin/doom sync -u -j $((`nproc`/4*3))
   '');