Remove old JSTests config

R=machenbach@chromium.org, tmrts@chromium.org

Bug: chromium:923304
Change-Id: I65898b7edea8d696d957a8ba19809484e663cb27
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1533864
Commit-Queue: Sergiy Belozorov <sergiyb@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60399}