This CL fixes the syntax of an entry in variants.py for stress_snapshot
(which got introduced in
https://chromium-review.googlesource.com/c/v8/v8/+/3024147).

Change-Id: I8e25ce26d546a022dbf9c038719f3e7cfac1d250
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3031898
Auto-Submit: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75748}