Mark mod as failing on Vulkan (#3926)
Mark mod as failing on Vulkan (#3926)

This passes on Swiftshader but fails on real Turing GPUs.
https://source.cloud.google.com/results/invocations/aead115c-3aab-4499-9a91-efa304f85a5e/
iree-org/iree,google/iree,google/iree,iree-org/iree,google/iree,google/iree,google/iree,iree-org/iree,iree-org/iree,google/iree,iree-org/iree,iree-org/iree,iree-org/iree,google/iree