Turn on fuzzing for disabled map space to get additional test coverage.

Bug: v8:12578
Change-Id: I82c577c8c24b51df627c873fde95fb239e16d36f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3592892Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80012}