Remove traces of Feature Level 9_3 support from tests. Bug: angleproject:1284 Bug: angleproject:3042 Change-Id: Ic2f77d315e98c3b15c5fc8b0359168bce00867d4 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3213294 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>