[Vulkan] Fix compilation of `vulkan-shaders-gen` on w64devkit after `e31a4f6` (#8880)
* Fix compilation issue in `vulkan-shaders-gen`
https://github.com/ggerganov/llama.cpp/commit/e31a4f679779220312c165b0f5994c680a610e38 broke compilation on w64devkit. Including `algorithm` seems to fix that.
* Guard it under `#ifdef _WIN32`