message: no longer need to set CMP0074 CMake policy
  [ci skip]
diff: @@ -18,9 +18,6 @@ set(CMAKE_DISABLE_SOURCE_CHANGES ON)
  set(CMAKE_DISABLE_IN_SOURCE_BUILD ON)
  cmake_minimum_required(VERSION 3.1)
  -if(POLICY CMP0074)
  - cmake_policy(SET CMP0074 NEW) # since 3.12
  -endif()
  include(cmake/ospray_version.cmake)
  