lib: set stderr._destroy to dummyDestroy

This seems to be typo: we are setting stdout._destroy instead of
stderr._destroy in the getter of stderr.

PR-URL: https://github.com/nodejs/node/pull/24398


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>