.build-all.dhall: remove

.build-all.dhall

-let Prelude =
-        env:DHALL_PRELUDE
-      ? https://raw.githubusercontent.com/dhall-lang/dhall-lang/v20.1.0/Prelude/package.dhall
-          sha256:26b0ef498663d269e4dc6a82b0ee289ec565d683ef4c00d0ebdd25333a5a3c98
-
-let H = ./horizon-spec.dhall
-
-let toStep
-    : Text → Text
-    = λ(x : Text) → ".#${x}"
-
-let input = Prelude.Map.keys Text H.HaskellPackage.Type ./horizon.dhall
-
-let packages = Prelude.List.map Text Text toStep (input : List Text)
-
-in      "nix build -L --no-link "
-    ++  Prelude.List.fold
-          Text
-          packages
-          Text
-          (λ(x : Text) → λ(y : Text) → x ++ " " ++ y)
-          ""