Include path for Python.h in Windows builds

[julian-smith-artifex-com]

When cibuildwheel builds a Windows wheel, is there a way for setup.py to find out what include path to use when compiling, in order to pick up the correct Python.h?

On Unix one can use f'{sys.executable}-config --includes', but there doesn't seem to be an equivalent available on Windows when cibuildwheel runs setup.py inside a venv - for example the directory that contains the python executable looks like:

    C:\\Users\\jules\\AppData\\Local\\Temp\\cibw-run-slccscwn\\cp310-win_amd64\\build\\venv\\Scripts\\pip-3.10.exe
    C:\\Users\\jules\\AppData\\Local\\Temp\\cibw-run-slccscwn\\cp310-win_amd64\\build\\venv\\Scripts\\pip.exe
    C:\\Users\\jules\\AppData\\Local\\Temp\\cibw-run-slccscwn\\cp310-win_amd64\\build\\venv\\Scripts\\pip3.10.exe
    C:\\Users\\jules\\AppData\\Local\\Temp\\cibw-run-slccscwn\\cp310-win_amd64\\build\\venv\\Scripts\\pip3.exe
    C:\\Users\\jules\\AppData\\Local\\Temp\\cibw-run-slccscwn\\cp310-win_amd64\\build\\venv\\Scripts\\python.exe
    C:\\Users\\jules\\AppData\\Local\\Temp\\cibw-run-slccscwn\\cp310-win_amd64\\build\\venv\\Scripts\\pythonw.exe
    C:\\Users\\jules\\AppData\\Local\\Temp\\cibw-run-slccscwn\\cp310-win_amd64\\build\\venv\\Scripts\\wheel-3.10.exe
    C:\\Users\\jules\\AppData\\Local\\Temp\\cibw-run-slccscwn\\cp310-win_amd64\\build\\venv\\Scripts\\wheel.exe
    C:\\Users\\jules\\AppData\\Local\\Temp\\cibw-run-slccscwn\\cp310-win_amd64\\build\\venv\\Scripts\\wheel3.10.exe
    C:\\Users\\jules\\AppData\\Local\\Temp\\cibw-run-slccscwn\\cp310-win_amd64\\build\\venv\\Scripts\\wheel3.exe

In the past on Windows i've looked at all installed python versions by parsing the output from py -0p, but cibuildwheel builds wheels for python versions that are not known to py. So i'm a bit stuck now...

Any suggestions welcomed.

- Julian