bpo-41098: Doc: Add missing deprecated directives (GH-21162)

PyUnicodeEncodeError_Create has been deprecated with
`Py_DEPRECATED` macro. But it was not documented.

Doc/c-api/exceptions.rst

@@ -637,11 +637,21 @@ The following functions are used to create and modify Unicode exceptions from C.
    *object*, *length*, *start*, *end* and *reason*. *encoding* and *reason* are
    UTF-8 encoded strings.
 
+   .. deprecated:: 3.3 3.11
+
+      ``Py_UNICODE`` is deprecated since Python 3.3. Please migrate to
+      ``PyObject_CallFunction(PyExc_UnicodeEncodeError, "sOnns", ...)``.
+
 .. c:function:: PyObject* PyUnicodeTranslateError_Create(const Py_UNICODE *object, Py_ssize_t length, Py_ssize_t start, Py_ssize_t end, const char *reason)
 
    Create a :class:`UnicodeTranslateError` object with the attributes *object*,
    *length*, *start*, *end* and *reason*. *reason* is a UTF-8 encoded string.
 
+   .. deprecated:: 3.3 3.11
+
+      ``Py_UNICODE`` is deprecated since Python 3.3. Please migrate to
+      ``PyObject_CallFunction(PyExc_UnicodeTranslateError, "Onns", ...)``.
+
 .. c:function:: PyObject* PyUnicodeDecodeError_GetEncoding(PyObject *exc)
                 PyObject* PyUnicodeEncodeError_GetEncoding(PyObject *exc)
 

Include/cpython/pyerrors.h

@@ -145,7 +145,10 @@ PyAPI_FUNC(PyObject *) PyErr_ProgramTextObject(
     PyObject *filename,
     int lineno);
 
-/* Create a UnicodeEncodeError object */
+/* Create a UnicodeEncodeError object.
+ *
+ * TODO: This API will be removed in Python 3.11.
+ */
 Py_DEPRECATED(3.3) PyAPI_FUNC(PyObject *) PyUnicodeEncodeError_Create(
     const char *encoding,       /* UTF-8 encoded string */
     const Py_UNICODE *object,
@@ -155,7 +158,10 @@ Py_DEPRECATED(3.3) PyAPI_FUNC(PyObject *) PyUnicodeEncodeError_Create(
     const char *reason          /* UTF-8 encoded string */
     );
 
-/* Create a UnicodeTranslateError object */
+/* Create a UnicodeTranslateError object.
+ *
+ * TODO: This API will be removed in Python 3.11.
+ */
 Py_DEPRECATED(3.3) PyAPI_FUNC(PyObject *) PyUnicodeTranslateError_Create(
     const Py_UNICODE *object,
     Py_ssize_t length,