Enable E2E convert_int.mlir.test for vulkan-spirv backend.
Enable E2E convert_int.mlir.test for vulkan-spirv backend.

It is unblocked after storing i8 tensor is supported.

PiperOrigin-RevId: 286596374

iree-org/iree,iree-org/iree,google/iree,google/iree,iree-org/iree,google/iree,google/iree,iree-org/iree,google/iree,iree-org/iree,google/iree,iree-org/iree,google/iree,iree-org/iree