gh-101967: add a missing error check (#101968)

Author: Eclips4

Misc/NEWS.d/next/Core and Builtins/2023-02-16-23-19-01.gh-issue-101967.Kqr1dz.rst

@@ -0,0 +1 @@
+Fix possible segfault in ``positional_only_passed_as_keyword`` function, when new list created.

Python/ceval.c

@@ -1255,7 +1255,9 @@ positional_only_passed_as_keyword(PyThreadState *tstate, PyCodeObject *co,
 {
     int posonly_conflicts = 0;
     PyObject* posonly_names = PyList_New(0);
-
+    if (posonly_names == NULL) {
+        goto fail;
+    }
     for(int k=0; k < co->co_posonlyargcount; k++){
         PyObject* posonly_name = PyTuple_GET_ITEM(co->co_localsplusnames, k);