arrow-cpp: libnsl is not necessary for building (#162757)

libnsl dependency was preventing building arrow-cpp on darwin.
arrow-cpp builds on darwin without issues outside of nix. The official
instructions at
https://arrow.apache.org/docs/developers/cpp/building.html do not
mention libnsl as a dependency. Thus, this change removes libnsl from
both darwin and linux platforms.

pkgs/development/libraries/arrow-cpp/default.nix

@@ -19,7 +19,6 @@
 , grpc
 , gtest
 , jemalloc
-, libnsl
 , lz4
 , minio
 , ninja
@@ -39,7 +38,7 @@
 , zlib
 , zstd
 , enableShared ? !stdenv.hostPlatform.isStatic
-, enableFlight ? !stdenv.isDarwin # libnsl is not supported on darwin
+, enableFlight ? true
 , enableJemalloc ? !(stdenv.isAarch64 && stdenv.isDarwin)
   # boost/process is broken in 1.69 on darwin, but fixed in 1.70 and
   # non-existent in older versions
@@ -129,7 +128,6 @@ stdenv.mkDerivation rec {
     python3.pkgs.numpy
   ] ++ lib.optionals enableFlight [
     grpc
-    libnsl
     openssl
     protobuf
   ] ++ lib.optionals enableS3 [ aws-sdk-cpp openssl ]