[Python] Avoid InvalidStateError on cancel (project-chip#35380)

When the co-routine GetConnectedDevice() gets cancelled, the wait_for
call will cancel the future we are waiting for. However, the SDK still
calls the _DeviceAvailableCallback with an error (CHIP Error 0x00000074:
The operation has been cancelled). However, we can't set the future
result at this point as the co-routine is already cancelled.

Simply check the future state before setting the result.

Author: agners

src/controller/python/chip/ChipDeviceCtrl.py

@@ -1062,6 +1062,8 @@ def __init__(self, loop, future: asyncio.Future):
                 self._future = future
 
             def _deviceAvailable(self):
+                if self._future.cancelled():
+                    return
                 if self._returnDevice.value is not None:
                     self._future.set_result(self._returnDevice)
                 else: