[3.9] bpo-46104: Fix example broken by GH-30148 (GH-30203) (GH-30210)

See discussion in GH-30179.
(cherry picked from commit 7c5c3f7)


Co-authored-by: Alex Waygood <[email protected]>

Automerge-Triggered-By: GH:Fidget-Spinner

Author: miss-islington

Doc/library/typing.rst

@@ -362,7 +362,7 @@ value of type :data:`Any` and assign it to any variable::
    a = []          # OK
    a = 2           # OK
 
-   s = ''          # Inferred type of 's' is str
+   s: str = ''
    s = a           # OK
 
    def foo(item: Any) -> int: