The overload taking a `MicrotaskQueue*` was introduced in
cce33f37 but never actually implemented.

This aligns the constructor signature to actually work, and
aligns it with e.g. `MicrotasksScope`. The previous signature
without an `Isolate*` argument would not work, because there’s
no pointer back from a MicrotaskQueue to the Isolate.

Refs: https://chromium-review.googlesource.com/c/v8/v8/+/1414950
Bug: v8:8124
Change-Id: I5dbaabef54c8de2b48f6172808825a186971524d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1879901Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64584}