This CL renames the --d8-web-snapshot-api flag to explicitly mark it as
experimental, so that it is ignored by fuzzers.

Bug: v8:11525, v8:11706
Change-Id: Iff8a9d5697b60d0ade841773d1f0b537fcb19b70
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2922109Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Vicky Kontoura <vkont@google.com>
Cr-Commit-Position: refs/heads/master@{#74820}