Use lens-4.6.0.1 instead of lens-4.4

lens-4.4 doesn't build because it requires an old version of text.

pkgs/development/libraries/haskell/lens/4.6.0.1.nix

@@ -0,0 +1,34 @@
+# This file was auto-generated by cabal2nix. Please do NOT edit manually!
+
+{ cabal, bifunctors, comonad, contravariant, deepseq, distributive
+, doctest, exceptions, filepath, free, genericDeriving, hashable
+, hlint, HUnit, mtl, nats, parallel, primitive, profunctors
+, QuickCheck, reflection, semigroupoids, semigroups, simpleReflect
+, split, tagged, testFramework, testFrameworkHunit
+, testFrameworkQuickcheck2, testFrameworkTh, text, transformers
+, transformersCompat, unorderedContainers, vector, void
+}:
+
+cabal.mkDerivation (self: {
+  pname = "lens";
+  version = "4.6.0.1";
+  sha256 = "099hhkca39zxfj9xavd2rafzgm2r4nm8clngcsgcrn1qsy8knvz2";
+  buildDepends = [
+    bifunctors comonad contravariant distributive exceptions filepath
+    free hashable mtl parallel primitive profunctors reflection
+    semigroupoids semigroups split tagged text transformers
+    transformersCompat unorderedContainers vector void
+  ];
+  testDepends = [
+    deepseq doctest filepath genericDeriving hlint HUnit mtl nats
+    parallel QuickCheck semigroups simpleReflect split testFramework
+    testFrameworkHunit testFrameworkQuickcheck2 testFrameworkTh text
+    transformers unorderedContainers vector
+  ];
+  meta = {
+    homepage = "http://github.com/ekmett/lens/";
+    description = "Lenses, Folds and Traversals";
+    license = self.stdenv.lib.licenses.bsd3;
+    platforms = self.ghc.meta.platforms;
+  };
+})

pkgs/top-level/haskell-packages.nix

@@ -1535,7 +1535,8 @@ self : let callPackage = x : y : modifyPrio (newScope self x y); in
 
   lens_4_2 = callPackage ../development/libraries/haskell/lens/4.2.nix {};
   lens_4_4 = callPackage ../development/libraries/haskell/lens/4.4.nix {};
-  lens = self.lens_4_4;
+  lens_4_6_0_1 = callPackage ../development/libraries/haskell/lens/4.6.0.1.nix {};
+  lens = self.lens_4_6_0_1;
 
   lensAeson = callPackage ../development/libraries/haskell/lens-aeson {};