This reverts commit d7fcbba8.

Reason for revert: Speculatively reverting because of blocked roll

Original change's description:
> [sandbox] Increase ExternalPointerTable maximum capacity to 512MB
>
> Bug: v8:10391
> Change-Id: I383e11bdccf6fcaf13f29d25e1404545067d313e
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3891249
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Commit-Queue: Samuel Groß <saelo@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#83203}

Bug: v8:10391
Change-Id: Id3a374a1f87a6ec3889d2e81d169ad004744ca99
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3904605
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83305}