Merge pull request #9515 from etcwilde/ewilde/20240723-enable-cmp0156

🍒[CMake] Enable CMP0156 if available

Author: etcwilde

cmake/Modules/CMakePolicy.cmake

@@ -29,3 +29,11 @@ endif()
 if(POLICY CMP0144)
   cmake_policy(SET CMP0144 NEW)
 endif()
+
+# CMP0156: De-duplicate libraries on link lines based on linker capabilities.
+# New in CMake 3.29: https://cmake.org/cmake/help/latest/policy/CMP0156.html
+# Avoids the deluge of 'ld: warning: ignoring duplicate libraries' warnings when
+# building with the Apple linker.
+if(POLICY CMP0156)
+  cmake_policy(SET CMP0156 NEW)
+endif()