This decreases the snapshot size (we don't need to write the ID for the
string) and speeds up deserialization.

Bug: v8:11525
Change-Id: I8f48d2344a7fd895c746e6a3d26f6dbbdd11a062
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3494539Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79381}