writeDeno: use writeTextFile

This fixes writeDenoText, as toFile doesn't like slashes.

pkgs/default.nix

@@ -236,7 +236,7 @@ pkgs: oldpkgs: {
     pkgs.writeDash "/bin/${name}";
 
   writeDeno = name: text: let
-    script = builtins.toFile "${name}.deno" text;
+    script = pkgs.writeTextFile { name = "${name}.deno"; inherit  text; };
   in
     pkgs.writeDash name ''
       exec ${pkgs.deno}/bin/deno run \