Override treeSitter passthrough

flake.nix

@@ -7,9 +7,12 @@
   outputs = { self, nixpkgs, flake-utils, emacs-overlay }: let
     mkEmacs = pkgs: v: pkgs.emacsWithPackagesFromUsePackage {
       config = ./main.org;
-      package = pkgs."${v}${if pkgs.stdenv.isDarwin then "-macport" else "-pgtk"}";
+      package = (pkgs."${v}${if pkgs.stdenv.isDarwin then "-macport" else "-pgtk"}").overrideAttrs (old: {
+        passthru = old.passthru // {
+          treeSitter = true;
+        };
+      });;
       extraEmacsPackages = epkgs: with epkgs; [
-        vterm
         treesit-grammars.with-all-grammars
       ];
     };