Now that V8_SANDBOXED_POINTERS is enabled by default on every platform
if the sandbox is enabled, it is no longer necessary to have a separate
option to enable/disable sandboxed pointers.

Bug: chromium:1218005
Change-Id: I2ab4c7c758010007765a3b0595357ddecfe9f258
Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3840937Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Samuel Groß <saelo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82587}