Only run the test when locale 'bn' is supported

Bug: v8:9100
Change-Id: I455d77a7fb7495f1f866211084cdb68fceb8c871
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2130069
Commit-Queue: Frank Tang <ftang@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66956}