Blender Git Loki

CMake/macOS: Search for headers in Frameworks last.

https://devtalk.blender.org/t/libpng-version-mismatch/15799/

By default, `CMAKE_FIND_FRAMEWORK` is `FIRST`.

CMake searches headers and libraries separately. So library is found
in LIBDIR, and headers like those in Mono are detected before the
headers in LIBDIR, and we get a version mismatch.

So set the priority of Frameworks to `LAST`.

https://gitlab.kitware.com/cmake/cmake/-/issues/18921
https://gitlab.kitware.com/cmake/cmake/-/issues/16427

{rBbac91956ae97} tried to fix the same issue, but it didn't work.
It's fine to keep the changes made there, just removing the comment
that may give false sense of security.