scripts: Remove unreleased extension names
scripts: Remove unreleased extension names

Change-Id: Ia0270edcd17a8b8a33e390f781b7357208e7a676

KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers,KhronosGroup/Vulkan-LoaderAndValidationLayers