For the initial iteration, only the default resolver can be
serialized/deserialized. If `dns.setServers()` has been
called, we'll preserve the configured DNS servers in the snapshot.
We can consider exposing the serialization method if it becomes
necessary for user-land snapshots.
PR-URL: https://github.com/nodejs/node/pull/44633
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>