Isolate::isolate_key_ and Isolate::per_isolate_thread_data_key_ are
created in Isolate::InitializeOncePerProcess() and should be deleted in
Isolate::DisposeOncePerProcess().

Bug: v8:11914
Change-Id: Ic3000d21f86a9d419373ef7c777c21661f544fee
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3490712Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79341}