hnix: add missing patch

pkgs/development/haskell-modules/patches/hnix.patch

@@ -0,0 +1,24 @@
+From 06b12ab8a733d4de2a39060ba29c06e4ec1c1187 Mon Sep 17 00:00:00 2001
+From: Anton Latukha <anton.latukha@gmail.com>
+Date: Sun, 16 Jan 2022 18:16:50 +0200
+Subject: [PATCH] fix aeson <2 support
+
+---
+ src/Nix/Json.hs | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/src/Nix/Json.hs b/src/Nix/Json.hs
+index 3fe05269..329899e4 100644
+--- a/src/Nix/Json.hs
++++ b/src/Nix/Json.hs
+@@ -9,6 +9,8 @@ import qualified Data.Text.Lazy.Encoding       as TL
+ #if MIN_VERSION_aeson(2,0,0)
+ import qualified Data.Aeson.Key                as AKM
+ import qualified Data.Aeson.KeyMap             as AKM
++#else
++import           Nix.Expr.Types
+ #endif
+ import qualified Data.Vector                   as V
+ import           Nix.Atoms
+-- 
+2.34.1