graphics/vulkan-headers: update to 1.3.257

Force rebuild vulkan-loader to make sure vulkaninfo shows the new version.

Changes: https://github.com/KhronosGroup/Vulkan-Headers/compare/v1.3.256...v1.3.257
Reported by: Repology, portscout

(cherry picked from commit 824e859a9d399732113e0537cce26d934d13c089)