hnix 0.16

[sternenseemann]

Build fails with hnix >= 0.16:

Building library for nix-linter-0.2.0.4..
[1 of 8] Compiling Data.Pair        ( src/Data/Pair.hs, dist/build/Data/Pair.o, dist/build/Data/Pair.dyn_o )
[2 of 8] Compiling Nix.Linter.Tools.FreeVars ( src/Nix/Linter/Tools/FreeVars.hs, dist/build/Nix/Linter/Tools/FreeVars.o, dist/build/Nix/Linter/Tools/FreeVars.dyn_o )

src/Nix/Linter/Tools/FreeVars.hs:6:44: error:
    Module ‘Nix.TH’ does not export ‘freeVars’
  |
6 | import           Nix.TH                   (freeVars)
  |                                            ^^^^^^^^
[3 of 8] Compiling Nix.Linter.Traversals ( src/Nix/Linter/Traversals.hs, dist/build/Nix/Linter/Traversals.o, dist/build/Nix/Linter/Traversals.dyn_o )
[4 of 8] Compiling Nix.Linter.Utils ( src/Nix/Linter/Utils.hs, dist/build/Nix/Linter/Utils.o, dist/build/Nix/Linter/Utils.dyn_o )
[5 of 8] Compiling Nix.Linter.Types ( src/Nix/Linter/Types.hs, dist/build/Nix/Linter/Types.o, dist/build/Nix/Linter/Types.dyn_o )