Fix typo in typing.rst (GH-22625)

Doc/library/typing.rst

@@ -1723,7 +1723,7 @@ Constant
 
       If ``from __future__ import annotations`` is used in Python 3.7 or later,
       annotations are not evaluated at function definition time.
-      Instead, the are stored as strings in ``__annotations__``,
+      Instead, they are stored as strings in ``__annotations__``,
       This makes it unnecessary to use quotes around the annotation.
       (see :pep:`563`).