fix(nvim): set useGlobalPackages

Otherwise it causes massive rebuilds T-T

nvim/default.nix

@@ -9,7 +9,6 @@ in
     (import ./standalone.nix)
     (lib.mkIf cfg.enable {
       enable = true;
-      nixpkgs.useGlobalPackages = true;
       defaultEditor = lib.mkDefault true;
       jhome.nvim = cfg;
     })

nvim/standalone.nix

@@ -10,6 +10,7 @@
 
   config = {
     withRuby = false;
+    nixpkgs.useGlobalPackages = true;
     globals.mapleader = " ";
     # Appearance
     colorschemes.gruvbox = {