VertexAttributeTest.DrawArraysWithAlignedAndUnalignedBufferOffset/ES2_D3D11
flakes on all Windows platforms. Supressing the failure while we
investigate.

Bug: angleproject:5258
Change-Id: I25dbdd4201d02fe32d37c4ca9527f86093f1c243
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2505480Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>