util: update set iterator entries inspection

The inspection output for Set#entries() was wrong so far as it did
not return an array as it should have. That was a bug in V8 that is
now fixed and the code in Node.js has to be updated accordingly.

PR-URL: https://github.com/nodejs/node/pull/25941
Fixes: https://github.com/nodejs/node/issues/24629


Reviewed-By: Michaël Zasso <targos@protonmail.com>