bpo-41625: Do not add os.splice on AIX due to compatibility issues (GH-23608)

diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 3e6e658..d9eb62f 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -10370,7 +10370,7 @@ os_copy_file_range_impl(PyObject *module, int src, int dst, Py_ssize_t count,
 }
 #endif /* HAVE_COPY_FILE_RANGE*/
 
-#ifdef HAVE_SPLICE
+#if (defined(HAVE_SPLICE) && !defined(_AIX))
 /*[clinic input]
 
 os.splice