TransformFeedbackTest.RecordAndDrawWithScissorTest is flaky on
"Mac Pro FYI Release (AMD)", so suppressing for now.

Bug: chromium:1135841
Test: TransformFeedbackTest.RecordAndDrawWithScissorTest
Change-Id: If610d7868950d1e2663c52b5194f6065a5900525
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2461455Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>