[unittests] Update PlatformUsesGuardPages test status

The test doesn't fail anymore after it was updated to check platforms
with page size > 4096:

402806e8
("[cppgc][unittests] Only expect guard pages support on 4k platforms.")

R=jkummerow@chromium.org

Bug: v8:11587
Change-Id: I6be93e9561b9db0d0f948c5e12fea6a067eb0a76
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2813538


Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73857}