Use an atomic marking state in all builds - even builds with concurrent
marking disabled. This will allow us to simplify our code a bit.

This CL starts by always using MajorMarkingState for
MarkCompactCollector::MarkingState and removing V8_ATOMIC_MARKING_STATE.

Bug: v8:12470
Change-Id: I88a65647fb2142a63b2b51fc21391c8ef1baa82d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3314864
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78241}