[3.12] gh-113538: Don't error in stream reader protocol callback when task is cancelled (GH-113690) (#113713)

(cherry picked from commit 4681a5271a)

Co-authored-by: Guido van Rossum <guido@python.org>

Lib/asyncio/streams.py

@@ -246,6 +246,9 @@ class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
                                             self._stream_writer)
             if coroutines.iscoroutine(res):
                 def callback(task):
+                    if task.cancelled():
+                        transport.close()
+                        return
                     exc = task.exception()
                     if exc is not None:
                         self._loop.call_exception_handler({