Message tests check the output of a test against an expected file.
Executing with --stress-opt changes the output, since the test will be
run multiple times. For that reason, most message tests explicitly add
the --no-stress-opt flag.

Since this is redundant, and not a per-test setting, just configure this
globally for all message tests instead.

R=machenbach@chromium.org

Bug: v8:12425
Change-Id: I52f1b43da2781fcb6f6bd37e67d483ca69c1c929
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3471637Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79164}