Can't build PyImath_d on Windows without debug Python build

[SimonBoorer]

On Windows pyconfig.h automatically links to debug Python builds if _DEBUG is defined:
https://github.com/python/cpython/blob/v3.10.9/PC/pyconfig.h#L270-L271

Boost Python wraps this so that it can be compiled in debug mode without requiring a debug build of Python:
https://github.com/boostorg/python/blob/boost-1.76.0/include/boost/python/detail/wrap_python.hpp#L23-L48

This is the default behaviour and can be controlled using BOOST_DEBUG_PYTHON.

Because PyImath headers include Python.h directly this bypasses the Boost python wrapper causing link incompatibility.

These headers should include boost/python/detail/wrap_python.hpp instead. Other libraries (e.g. USD) wrap BOOST_DEBUG_PYTHON in a cmake option, e.g.: PixarAnimationStudios/OpenUSD#1478

[meshula]

This is a reasonable suggestion, we could do that. Are you interested in submitting a PR? I don't personally work with debug python builds on windows, so I'm not really set up to try this locally.