Failure to install from PyPI on Python 3.13

[PhilippWendler]

If I attempt to pip install pystemd on Python 3.13, it attempts to install 0.13.2 but fails with the following error:

[...]
      building 'pystemd.cutils' extension
      creating build/temp.linux-x86_64-cpython-313/pystemd
      gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -fPIC -I/usr/local/include/python3.13 -c pystemd/cutils.c -o build/temp.linux-x86_64-cpython-313/pystemd/cutils.o
      pystemd/cutils.c:850:1: warning: ‘Py_UNICODE’ is deprecated [-Wdeprecated-declarations]
        850 | static CYTHON_INLINE size_t __Pyx_Py_UNICODE_strlen(const Py_UNICODE *u) {
            | ^~~~~~
      pystemd/cutils.c: In function ‘__Pyx_Py_UNICODE_strlen’:
      pystemd/cutils.c:851:5: warning: ‘Py_UNICODE’ is deprecated [-Wdeprecated-declarations]
        851 |     const Py_UNICODE *u_end = u;
            |     ^~~~~
      pystemd/cutils.c: In function ‘__Pyx_PyInt_As_int’:
      pystemd/cutils.c:2379:27: error: too few arguments to function ‘_PyLong_AsByteArray’
       2379 |                 int ret = _PyLong_AsByteArray((PyLongObject *)v,
            |                           ^~~~~~~~~~~~~~~~~~~
      In file included from /usr/local/include/python3.13/longobject.h:107,
                       from /usr/local/include/python3.13/Python.h:81,
                       from pystemd/cutils.c:22:
      /usr/local/include/python3.13/cpython/longobject.h:111:17: note: declared here
        111 | PyAPI_FUNC(int) _PyLong_AsByteArray(PyLongObject* v,
            |                 ^~~~~~~~~~~~~~~~~~~
      pystemd/cutils.c: In function ‘__Pyx_PyInt_As_long’:
      pystemd/cutils.c:2651:27: error: too few arguments to function ‘_PyLong_AsByteArray’
       2651 |                 int ret = _PyLong_AsByteArray((PyLongObject *)v,
            |                           ^~~~~~~~~~~~~~~~~~~
      /usr/local/include/python3.13/cpython/longobject.h:111:17: note: declared here
        111 | PyAPI_FUNC(int) _PyLong_AsByteArray(PyLongObject* v,
            |                 ^~~~~~~~~~~~~~~~~~~
      error: command '/usr/bin/gcc' failed with exit code 1

(Full reproducer podman run --rm -it python:3.13 bash -c 'apt-get update && apt-get install libsystemd-dev && pip install pystemd')

If I install from GitHub with pip install git+https://github.com/systemd/pystemd it works. I believe this is not due to 0.13.2 being older than 5cdee54 but because the .tar.gz on PyPI includes the file pystemd/cutils.c, which is auto-generated by Cython but in this version is incompatible with Python 3.13. The GitHub repo does not contain cutils.c, so I assume it is generated during build in a matching version.

I have no experience with C extensions for Python and do not know whether it is intended that the archive on Python contains the generated C files. But could you please upload a version to PyPI that is installable on Python 3.13? I suspect either the generated C code needs to be updated or removed.