Fail `make install` and `./setup.py build`

[Serge3leo]

I've only checked python 3.9 and 3.12, but it's probably not a python problem, but Cython or setuptools problem.

$ pip list
Package    Version
---------- -------
Cython     3.0.11
pip        24.3.1
setuptools 75.2.0
wheel      0.44.0
$ make 
CYTHONIZE=1 ./setup.py build
running build
running build_py
warning: build_py: byte-compiling is disabled, skipping.

running build_ext
building 'cypack.utils' extension
clang -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -iwithsysroot/System/Library/Frameworks/System.framework/PrivateHeaders -iwithsysroot/Applications/Xcode.app/Contents/Developer/Library/Frameworks/Python3.framework/Versions/3.9/Headers -arch arm64 -arch x86_64 -Werror=implicit-function-declaration -Wno-error=unreachable-code -I/Applications/Xcode.app/Contents/Developer/Library/Frameworks/Python3.framework/Versions/3.9/include/python3.9 -c src/cypack/utils.c -o build/temp.macosx-10.9-universal2-3.9/src/cypack/utils.o
clang: error: no such file or directory: 'src/cypack/utils.c'
clang: error: no input files
error: command '/opt/local/bin/clang' failed with exit code 1
make: *** [build] Error 1

[Serge3leo]

Bug at first line setup.py:

#!/usr/bin/python3

Incompatible with virtualenv/pipenv/conda/mamba...

This line need remove or, may bee, replace to:

#!/usr/bin/env python3

Pull request with this and tests improvements for macOS and Windows will be later....