gh-101498 : Fix asyncio.Timeout example in docs (GH-101499)

Doc/library/asyncio-task.rstGH-timeout
(cherry picked from commit 95fb0e0)

Co-authored-by: Raj <[email protected]>

Author: miss-islington

Doc/library/asyncio-task.rst

@@ -666,7 +666,7 @@ Timeouts
             except TimeoutError:
                 pass
 
-            if cm.expired:
+            if cm.expired():
                 print("Looks like we haven't finished on time.")
 
     Timeout context managers can be safely nested.