gh-107980: fix doc role for asyncio.timeouts (#108126)

Author: Tinche

Doc/library/asyncio-task.rst

@@ -631,9 +631,9 @@ Shielding From Cancellation
 Timeouts
 ========
 
-.. coroutinefunction:: timeout(delay)
+.. function:: timeout(delay)
 
-    An :ref:`asynchronous context manager <async-context-managers>`
+    Return an :ref:`asynchronous context manager <async-context-managers>`
     that can be used to limit the amount of time spent waiting on
     something.
 
@@ -724,7 +724,7 @@ Timeouts
 
     .. versionadded:: 3.11
 
-.. coroutinefunction:: timeout_at(when)
+.. function:: timeout_at(when)
 
    Similar to :func:`asyncio.timeout`, except *when* is the absolute time
    to stop waiting, or ``None``.