nix: make Perl bindings use matching Nix version

Previously, 'nix_2_6.perl-bindings' (for example) was built from the Nix 2.6
but linked against 'nix' (the latest version). This usually causes the build
to fail.

pkgs/tools/package-management/nix/common.nix

@@ -53,8 +53,8 @@ in
 , confDir
 , stateDir
 , storeDir
-}:
-stdenv.mkDerivation {
+}: let
+self = stdenv.mkDerivation {
   pname = "nix";
 
   version = "${version}${suffix}";
@@ -209,6 +209,7 @@ stdenv.mkDerivation {
   passthru = {
     inherit aws-sdk-cpp boehmgc;
 
-    perl-bindings = perl.pkgs.toPerlModule (callPackage ./nix-perl.nix { inherit src version;  });
+    perl-bindings = perl.pkgs.toPerlModule (callPackage ./nix-perl.nix { nix = self; });
   };
-}
+};
+in self

pkgs/tools/package-management/nix/nix-perl.nix

@@ -8,14 +8,11 @@
 , autoreconfHook
 , autoconf-archive
 , nlohmann_json
-
-, version
-, src
 }:
 
 stdenv.mkDerivation {
   pname = "nix-perl";
-  inherit version src;
+  inherit (nix) version src;
 
   postUnpack = "sourceRoot=$sourceRoot/perl";