Vulkan is being updated on Fuchsia. Disable validation to unblock it.

Bug: fuchsia:73208
Change-Id: I8a6eecc16ef021d379cfcca8795896a6e6dae11c
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2876070Reviewed-by: Tim Van Patten <timvp@google.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>