Previously we've added has_scheduled_exception DCHECKs that were a bit
too strict in some cases.

- Remove unused exception_out param for TryRunMicrotasks
- Simplify overzealous DCHECK and clean up MicrotaskQueue::RunMicrotasks

Change-Id: I3a945a731573b6b3e44e17487fb8bf871b9a6793
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3789504
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82131}