gh-125289: Update sample code in asyncio-task.rst (GH-125292)

* Update sample code in asyncio-task.rst

This will change **coroutines** sample code in the **Awaitables** section and make the example clearer.

* Update Doc/library/asyncio-task.rst

Revert the added print

Co-authored-by: Carol Willing <carolcode@willingconsulting.com>

* Update Doc/library/asyncio-task.rst

Co-authored-by: Carol Willing <carolcode@willingconsulting.com>

---------

Co-authored-by: Carol Willing <carolcode@willingconsulting.com>

Doc/library/asyncio-task.rst

@@ -158,7 +158,7 @@ other coroutines::
         # Nothing happens if we just call "nested()".
         # A coroutine object is created but not awaited,
         # so it *won't run at all*.
-        nested()
+        nested()  # will raise a "RuntimeWarning".
 
         # Let's do it differently now and await it:
         print(await nested())  # will print "42".