fs: replace pushValueToArray with pure C++ API

Instead of calling into JS from C++ to push values into an array,
use the new Array::New API that takes a pointer and a length
directly.

PR-URL: https://github.com/nodejs/node/pull/24125
Refs: https://github.com/v8/v8/commit/0483e9a9abe77a73632fd85b9c0cd608efa9aa0d


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Yang Guo <yangguo@chromium.org>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Refael Ackermann <refack@gmail.com>