Vulkan: Remove support for pipeline cache control For current and upcoming uses for pipeline caches the benefits of having an externally synchronized pipeline cache is minimal at best. Remove support for that and have all caches be internally synchronized by the Vulkan driver. Bug: angleproject:8601 Change-Id: Ic5d9740934641f61b527094aa301e27302b02a57 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5375102 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>