[3.14] gh-132775: Unrevert "Add _PyCode_VerifyStateless()" (gh-133625)

This reverts commit 3c73cf5 (gh-133497), which itself reverted
the original commit d270bb5 (gh-133221).

We reverted the original change due to failing android tests.
The checks in _PyCode_CheckNoInternalState() were too strict,
so we've relaxed them.

Include/internal/pycore_function.h

@@ -35,6 +35,13 @@ PyFunctionObject *_PyFunction_LookupByVersion(uint32_t version, PyObject **p_cod
 extern PyObject *_Py_set_function_type_params(
     PyThreadState* unused, PyObject *func, PyObject *type_params);
 
+
+/* See pycore_code.h for explanation about what "stateless" means. */
+
+PyAPI_FUNC(int)
+_PyFunction_VerifyStateless(PyThreadState *, PyObject *);
+
+
 #ifdef __cplusplus
 }
 #endif