This wraps CagedHeapLocalData in #if defined(CPPGC_CAGED_HEAP)

Bug: v8:12231
Change-Id: I462ddbbde2308e8d786fb99d6a557c1dcaea8a4e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3695586
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Auto-Submit: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81038}