haskell-dhall: disable the test suite

Dhall 1.31.x still attempts to access the network during its
test suite run, i.e. it attempts to connect to github.com.

pkgs/development/haskell-modules/configuration-nix.nix

@@ -720,10 +720,9 @@ self: super: builtins.intersectAttrs super {
   # break infinite recursion with base-orphans
   primitive = dontCheck super.primitive;
 
-  # dhall-1.29.0 tests access the network.  This override can be removed when
-  # dhall_1_29_0 is no longer used, since more recent versions of dhall don't
-  # access the network in checks.
+  # dhall's tests access the network.
   dhall_1_29_0 = dontCheck super.dhall_1_29_0;
+  dhall_1_31_1 = dontCheck super.dhall_1_31_1;
 
   cut-the-crap =
     let path = pkgs.stdenv.lib.makeBinPath [ pkgs.ffmpeg ];