Solution of enabling OpenMP support for macOS

[vainPointer]

Describe the Issue!

The document of QuTiP said installing from the source code by python setup.py install --with-openmp doesn't support for macOS. But this is actually easy to deal with.

Step 1. Install GNU GCC and OpenMP from home-brew
$ brew install gcc libomp

Step 2. Export environment CC CXX instead of /usr/bin/gcc by /usr/local/bin/gcc-13
$ export CC=`which gcc-13` $ export CXX=`which g++-13`

Now it is worked in my environment that python setup.py build --with-openmp generates a OpenMP edition QuTiP.

And as for INTEL MKL supporting info, the judgment for macOS is different, you can find the way here to get this information rather than hasattr(config,'mkl_info').