The patch was added to fix a compilation error with llama.cpp bundled
in Groonga. However, this issue was already fixed upstream in llama.cpp b4683.
ref: 19b392d58d
Since Groonga over v15.0.8 upgraded to llama.cpp b5129 on April 14 (which includes
the fix), the patch is no longer needed. Remove the patch file and the workaround build steps.