Looks like you forgot to add the cmake directory to the release artifact.
CMake Error: File /tmp/test/llhttp-release-v9.4.0/cmake/llhttpConfig.cmake.in does not exist.
CMake Error at /usr/share/cmake/Modules/CMakePackageConfigHelpers.cmake:519 (configure_file):
configure_file Problem configuring file
Call Stack (most recent call first):
CMakeLists.txt:102 (configure_package_config_file)
Looks like you forgot to add the cmake directory to the release artifact.