Enable Dawn AMD Mac experimental tester

Enables the Dawn AMD Mac experimental tester to start triggering tests
on Mac 14.3.1.

Bug: 327017900
Change-Id: Ia2efb586e53379addb5525c8c075900598cf005f
Include-Ci-Only-Tests: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5345147


Auto-Submit: Brian Sheedy <bsheedy@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1271721}