Replace internal API _PyBytes_Join, removed in Python 3.13

Author: musicinmybrain

src/zlib_ng/zlib_ngmodule.c

@@ -2810,7 +2810,7 @@ GzipReader_readall(GzipReader *self, PyObject *Py_UNUSED(ignore))
         Py_DECREF(chunk_list);
         return NULL;
     }
-    PyObject *ret = _PyBytes_Join(empty_bytes, chunk_list);
+    PyObject *ret = PyObject_CallMethod(empty_bytes, "join", "O", chunk_list);
     Py_DECREF(empty_bytes);
     Py_DECREF(chunk_list);
     return ret;