ggml-vulkan: remove unused find_program(glslc)

[guusw]

It's unused and already found by FindVulkan.cmake in the parent CMakeLists.
Also having this find_program here directly prevents usage of hit variables like VULKAN_ROOT which are used by FindVulkan (find_package(Vulkan))

[bandoti]

This change would break cross-compiling. The reason the glslc program is found in isolation here is because that executable will be binary compatible with the build machine, which might be a different architecture than what is found with Vulkan library.

I am working on adding a CI build for this and I will put a comment here so it doesn't cause confusion moving forward.

[bandoti]

That being said, we can investigate adding a separate find_package(Vulkan ...) explicitly for the glslc package and ignoring the cross-compile paths.

Is there a specific issue this is causing?

[bandoti]

After I started adding the CI change #12428 to put regression tests on cross-compiling, I am seeing this application actually doesn't need glslc at all (as this PR suggests), because it is passed as a command-line argument. We can likely merge this in just checking to make sure. 😅

[bandoti]

Looks good to me. I am following up with #12428 to add regression tests to CI for cross-compiling.