Dhall.Pretty updated; fails to build on Nix

[toastal]

src/Spago/Dhall.hs:39:11: error:
    • Couldn't match expected type ‘Maybe Dhall.Pretty.CharacterSet’
                  with actual type ‘Dhall.Pretty.CharacterSet’
    • In the first argument of ‘Dhall.Format.Format’, namely
        ‘Dhall.Pretty.ASCII’
      In the second argument of ‘(.)’, namely
        ‘Dhall.Format.Format
           Dhall.Pretty.ASCII NoCensor
           (PossiblyTransitiveInputFile (Text.unpack pathText) NonTransitive)’
      In the expression:
        Dhall.Format.format
          . Dhall.Format.Format
              Dhall.Pretty.ASCII NoCensor
              (PossiblyTransitiveInputFile (Text.unpack pathText) NonTransitive)
   |
39 |           Dhall.Pretty.ASCII
   |           ^^^^^^^^^^^^^^^^^^

I believe this came up in the discussion in ASCII vs. Unicode discussion on the Dhall Discourse, but now the autoformatter can deduce which style the user is using. The update happened in dhall-haskell last month with this commit. I suppose this library at least needs the library updated.

I would assume spago should also be "smart" about formatting too even if PureScript, the org?, wants to keep ASCII by default?

[f-f]

I don't have a strong preference for this, so using the new encoding detection machinery sounds good to me.
I have no plans to update to the new Dhall version myself soon, but I'll gladly accept a PR for that change 🙂

[toastal]

I wish I was a Haskell programmer so I could help. I may have to switch spago to easy-purescript-nix in the meantime.

[f-f]

Fixed in #739