BUG: Fix check for including old cmake documentation code

Change-Id: I4d77548f49fe01da14dbf1a4839e3d65ba0e678a

Author: gdevenyi

Utilities/Doxygen/CMakeLists.txt

@@ -6,7 +6,7 @@
 # (preserving any auxiliary behavior it provides on era-original toolchains)
 # and inline the BUILD_DOCUMENTATION option on CMake >= 4.0 where the file
 # no longer ships.
-if(CMAKE_VERSION VERSION_LESS 4.0)
+if(CMAKE_VERSION VERSION_LESS 3.18)
   include(${CMAKE_ROOT}/Modules/Documentation.cmake)
 else()
   option(BUILD_DOCUMENTATION "Build the documentation (Doxygen)." OFF)