bpo-42451: Indicate that PyTuple_GetItem does not support negative indices (GH-23529)

Author: 0xYasser

Doc/c-api/tuple.rst

@@ -57,7 +57,7 @@ Tuple Objects
 .. c:function:: PyObject* PyTuple_GetItem(PyObject *p, Py_ssize_t pos)
 
    Return the object at position *pos* in the tuple pointed to by *p*.  If *pos* is
-   out of bounds, return ``NULL`` and set an :exc:`IndexError` exception.
+   negative or out of bounds, return ``NULL`` and set an :exc:`IndexError` exception.
 
 
 .. c:function:: PyObject* PyTuple_GET_ITEM(PyObject *p, Py_ssize_t pos)