maybe I miss something

but I have downloaded the last fedora:rawhide with docker, just update it via dnf update and install all the dependencies for git and python

docker --rm -it fedora:rawhide /bin/bash

dnf update
dnf install git-core
dnf builddep python3

git clone --depth=1 https://github.com/python/cpython
cd cpython
./configure && make

and I have no issue with ctypes.

What are your instructions for the build?

Thank you