install(EXPORT GostEngineConfig DESTINATION share/cmake/GostEngine) will to a path like this:
/usr/GostEngine/share/cmake/GostEngine/GostEngineConfig.cmake
which is not standard or expected. These files should be installed to:
/usr/share/cmake/GostEngine/GostEngineConfig.cmake
which can be done by changing the installation line to:
install(EXPORT GostEngineConfig DESTINATION share/cmake/GostEngine)