Turn on fuzzing for Maglev to get additional test coverage.

Bug: v8:7700
Change-Id: I5b72d851639e31dff1bd91361cd81ad448c2d69e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3629334
Auto-Submit: Jakob Linke <jgruber@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80416}