Don't install randomx.h

This breaks for some reason under focal, but also we don't want this
header for oxen-core as it is used purely internally.

CMakeLists.txt

@@ -221,13 +221,11 @@ endif()
 set_property(TARGET randomx PROPERTY POSITION_INDEPENDENT_CODE ON)
 set_property(TARGET randomx PROPERTY CXX_STANDARD 11)
 set_property(TARGET randomx PROPERTY CXX_STANDARD_REQUIRED ON)
-set_property(TARGET randomx PROPERTY PUBLIC_HEADER src/randomx.h)
 
 include(GNUInstallDirs)
 install(TARGETS randomx
   LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
-  PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
 add_executable(randomx-tests
   src/tests/tests.cpp)