LunarG no longer offers the 1.3.224.1 Vulkan SDK used by CI. This means that anyone who doesn't already have it in their fork's CI cache can't run the VSG's CI.
Changing the version requested will probably work, although I see that with 1.3.261.1, they switched the compression from .gz to .xz, so the Action we're using may need to be switched if we bump the version a long way and it turns out it makes assumptions about the extraction command to run.