pythongh-89547: typing.rst: Add note about change in behavior with Cl…

…assVar/Final (python#116686)

Doc/library/typing.rst

@@ -1233,6 +1233,10 @@ These can be used as types in annotations. They all support subscription using
 
    .. versionadded:: 3.5.3
 
+   .. versionchanged:: 3.13
+
+      :data:`ClassVar` can now be nested in :data:`Final` and vice versa.
+
 .. data:: Final
 
    Special typing construct to indicate final names to type checkers.
@@ -1256,6 +1260,10 @@ These can be used as types in annotations. They all support subscription using
 
    .. versionadded:: 3.8
 
+   .. versionchanged:: 3.13
+
+      :data:`Final` can now be nested in :data:`ClassVar` and vice versa.
+
 .. data:: Required
 
    Special typing construct to mark a :class:`TypedDict` key as required.