Blender Git Loki

CMake/deps: Append platform CFLAGS and LDFLAGS to Python build to ensure compatibility with minimum macOS version

Similarly to other dependencies, the Python build should make use of the default CMake arguments. On macOS, for example, these arguments are required to set the deployment target correctly.

See also: https://devtalk.blender.org/t/compiling-latest-branch-on-macos-fails-undefined-symbol/17649

Reviewed By: brecht, sybren

Differential Revision: https://developer.blender.org/D10498