`yargs().env()` always fails in deno runtime

[reosablo]

This is a small reproducible code:

// example.ts
import yargs from "https://deno.land/x/yargs@v17.0.1-deno/deno.ts";
yargs().env().parse([]);

deno run example.ts              # uncaught error: permission denied
deno run --allow-env example.ts  # uncaught error: Object.keys(undefined)

Maybe, that's because env() in deno.ts:12:14 returns nothing and doesn't handle PermissionDenied errors like this:

  env: () => {
    Deno.env.toObject()
  },

[MaikuMori]

Can I make PR to fix this?

[reosablo]

@MaikuMori I didn't follow this issue but it seems to have been fixed in #432.