This is an example Python package that builds ctypes-based cross-Python wheels using cibuildwheel.
These wheels have the wheel tag py3-none-PLATFORM, meaning that one wheel
will work for any version of Python 3, including PyPy. So you'll end up with
one wheel per OS/architecture, which is considerably fewer than building one
for each Python.
Thanks to @himbeles for some of the code from their sample ctypes project