@0cc4m similar to past issue (#12294)..

Github Actions CI Windows Vulkan builds don't support VK_KHR_shader_bfloat16 yet..
for ex. latest:
https://github.com/ggml-org/llama.cpp/releases/download/b5686/llama-b5686-bin-win-vulkan-x64.zip
in contrast to:
https://github.com/ggml-org/llama.cpp/releases/download/b5686/llama-b5686-bin-ubuntu-vulkan-x64.zip
that has support for it..

Nvidia drivers and SDK are stable now for bfloat16 support..

fix for getting bfloat16 Vulkan support ((#12554)) on Windows builds is easy:

solution is:
to update:
VULKAN_VERSION: 1.4.309.0
to
VULKAN_VERSION: 1.4.313.0
in:
https://github.com/ggml-org/llama.cpp/blob/master/.github/workflows/build.yml#L686

@0cc4m can fix it?

thanks..