lkl: use python3

pkgs/applications/virtualization/lkl/default.nix

···
-{ lib, stdenv, fetchFromGitHub, bc, python, bison, flex, fuse, libarchive
+{ lib, stdenv, fetchFromGitHub, bc, python3, bison, flex, fuse, libarchive
 , buildPackages }:
 
 stdenv.mkDerivation rec {
···
 
   outputs = [ "dev" "lib" "out" ];
 
-  nativeBuildInputs = [ bc bison flex python ];
+  nativeBuildInputs = [ bc bison flex python3 ];
 
   buildInputs = [ fuse libarchive ];