Don't expose %SerializeDeserializeNow() to fuzzers

The runtime function is not currently fuzzing-safe and will frequently
cause crashes if used by fuzzers.

Bug: 353971258, 353685107
Change-Id: I692bbd752fc86930e4ea014d2557247422b6ba9a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5725353


Auto-Submit: Samuel Groß <saelo@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#95136}