Missing pkgconfig.mk and .in files in v6.0.0a1 sdist archive

[Antelox]

Work environment

Questions	Answers
OS/arch/bits	all
Architecture	all
Source of Capstone	git clone , default on next branch.
Version/git commit	v6.0.0alpha1

Expected behavior

Installing capstone using sdist archive should work same as if installing using a wheel package

Actual behavior

Since setup.py derives the capstone version by reading the file pkgconfig.mk, if it is missing it can not go ahead and raises an error:

An excerpt of the error:

        File "/tmp/pip-build-env-c5v0x3zx/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 320, in run_setup
          exec(code, locals())
        File "<string>", line 34, in <module>
      FileNotFoundError: [Errno 2] No such file or directory: '/tmp/pip-req-build-v01u8tgj/src/pkgconfig.mk'

In addition, the .in files are missing too and they are required to actually build the capstone library.

The above error happens in other platforms too.

Steps to reproduce the behavior

wget https://files.pythonhosted.org/packages/3c/d3/8dd39fe31323abe482a1249f5533ee05b610f35b586d0be3d2c382f5baf0/capstone-6.0.0a1.tar.gz && pip install capstone-6.0.0a1.tar.gz