It was added years ago and in 2017 it was enabled by default[1], which
means enough time has passed and we can remove the flag.

[1]: https://chromium-review.googlesource.com/c/v8/v8/+/528076/

Change-Id: I059417d4683910e86ebfddd93f504006094fa342
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2947406Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75039}