dns: report out of memory properly

This addresses a part of a TODO by properly reporting an out of
memory error to the user instead of reporting `ENOTFOUND`.

PR-URL: https://github.com/nodejs/node/pull/20317


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>