CMake: Set policy CMP0102 to NEW

Fixes warning:

CMake Warning (dev) at /usr/share/cmake-3.22/Modules/FindJPEG.cmake:142 (mark_as_advanced):
  Policy CMP0102 is not set: The variable named "JPEG_LIBRARY" is not in the
  cache.  This results in an empty cache entry which is no longer created
  when policy CMP0102 is set to NEW.  Run "cmake --help-policy CMP0102" for
  policy details.  Use the cmake_policy command to set the policy and
  suppress this warning.

Author: evan-charmworks

CMakeLists.txt

@@ -23,6 +23,10 @@ message("##################################################################")
 
 if(CMAKE_VERSION VERSION_GREATER 3.12 OR CMAKE_VERSION VERSION_EQUAL 3.12)
   cmake_policy(SET CMP0075 NEW)
+
+  if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.17)
+    cmake_policy(SET CMP0102 NEW)
+  endif()
 endif()
 
 # Fortran is optional, so don't include it in LANGUAGES here