pythongh-105373: PyObject_SetAttr(NULL) is no longer deprecated

Remove the deprecation on the following functions:

* PyObject_SetAttr(obj, attr_name, NULL)
* PyObject_SetAttrString(obj, attr_name, NULL)
* PySequence_SetItem(obj, i, NULL)
* PySequence_SetSlice(obj, i1, i2, NULL)

Deprecation added by commit ed82604.

Doc/c-api/object.rst

@@ -81,9 +81,8 @@ Object Protocol
  return ``0`` on success. This is the equivalent of the Python statement
  ``o.attr_name = v``.
 
- If *v* is ``NULL``, the attribute is deleted. This behaviour is deprecated
- in favour of using :c:func:`PyObject_DelAttr`, but there are currently no
- plans to remove it.
+ Delete the attribute named *attr_name* if *v* is ``NULL``. The function
+ :c:func:`PyObject_DelAttr` is preferred to delete an attribute.
 
 
 .. c:function:: int PyObject_SetAttrString(PyObject *o, const char *attr_name, PyObject *v)
@@ -93,8 +92,8 @@ Object Protocol
  return ``0`` on success. This is the equivalent of the Python statement
  ``o.attr_name = v``.
 
- If *v* is ``NULL``, the attribute is deleted, but this feature is
- deprecated in favour of using :c:func:`PyObject_DelAttrString`.
+ Delete the attribute named *attr_name* if *v* is ``NULL``. The function
+ :c:func:`PyObject_DelAttrString` is preferred to delete an attribute.
 
 
 .. c:function:: int PyObject_GenericSetAttr(PyObject *o, PyObject *name, PyObject *value)

Doc/c-api/sequence.rst

@@ -69,8 +69,8 @@ Sequence Protocol
  is the equivalent of the Python statement ``o[i] = v``. This function *does
  not* steal a reference to *v*.
 
- If *v* is ``NULL``, the element is deleted, but this feature is
- deprecated in favour of using :c:func:`PySequence_DelItem`.
+ Delete the *i*\ th element if *v* is ``NULL``. The function
+ :c:func:`PySequence_DelItem` is preferred to delete an element.
 
 
 .. c:function:: int PySequence_DelItem(PyObject *o, Py_ssize_t i)
@@ -84,6 +84,9 @@ Sequence Protocol
  Assign the sequence object *v* to the slice in sequence object *o* from *i1* to
  *i2*. This is the equivalent of the Python statement ``o[i1:i2] = v``.
 
+ Delete the elements if *v* is ``NULL``. The function
+ :c:func:`PySequence_DelSlice` is preferred to delete elements.
+
 
 .. c:function:: int PySequence_DelSlice(PyObject *o, Py_ssize_t i1, Py_ssize_t i2)