Spec Text:
https://tc39.es/proposal-temporal/#sec-get-temporal.zoneddatetime.prototype.offset
https://tc39.es/proposal-temporal/#sec-get-temporal.zoneddatetime.prototype.offsetnanoseconds

Bug: v8:11544
Change-Id: Ia88d96b038117a8e528ff9d0cdb9a07fb7cbcda5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3385606Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80096}