nix: Update to latest nixpkgs#master

default.nix

@@ -28,12 +28,6 @@ let
       sha256 = tarballHash;
     };
 
-  nixpkgs-patched = (import nixpkgs { inherit overlays system; }).applyPatches {
-    name = "nixpkgs-patched";
-    src = nixpkgs;
-    patches = [ nix/split-sections-cross.patch ];
-  };
-
   allOverlays =
     import nix/overlays;
 
@@ -52,7 +46,7 @@ let
 
   # Evaluated expression of the Nixpkgs repository.
   pkgs =
-    import nixpkgs-patched { inherit overlays system; };
+    import nixpkgs { inherit overlays system; };
 
   postgresqlVersions =
     [
@@ -88,7 +82,7 @@ let
   inherit (pkgs.haskell) lib;
 in
 rec {
-  inherit nixpkgs-patched pkgs;
+  inherit nixpkgs pkgs;
 
   # Derivation for the PostgREST Haskell package, including the executable,
   # libraries and documentation. We disable running the test suite on Nix