[3.9] bpo-45097: Remove incorrect deprecation warnings in asyncio. (GH-28153)

Deprecation warnings about the loop argument were incorrectly emitted
in cases when the loop argument was used inside the asyncio library,
not from user code.

Lib/asyncio/runners.py

@@ -61,7 +61,7 @@ def _cancel_all_tasks(loop):
         task.cancel()
 
     loop.run_until_complete(
-        tasks.gather(*to_cancel, loop=loop, return_exceptions=True))
+        tasks._gather(*to_cancel, loop=loop, return_exceptions=True))
 
     for task in to_cancel:
         if task.cancelled():