[3.13] gh-141004: Document PyCode_Optimize (GH-141378) (GH-141515)

gh-141004: Document `PyCode_Optimize` (GH-141378)
(cherry picked from commit d7862e9b1b)

Co-authored-by: Peter Bierma <zintensitydev@gmail.com>

Doc/c-api/code.rst

@@ -211,6 +211,17 @@ bound into a function.
    .. versionadded:: 3.12
 
 
+.. c:function:: PyObject *PyCode_Optimize(PyObject *code, PyObject *consts, PyObject *names, PyObject *lnotab_obj)
+
+   This is a :term:`soft deprecated` function that does nothing.
+
+   Prior to Python 3.10, this function would perform basic optimizations to a
+   code object.
+
+   .. versionchanged:: 3.10
+      This function now does nothing.
+
+
 .. _c_codeobject_flags:
 
 Code Object Flags