Change receiver limit in mock_resampler

This receiver is only to forward messages to subscribers.
It doesn't need more then 1 last message.
No tests are broken after this.

Signed-off-by: Elzbieta Kotulska <elzbieta.kotulska@frequenz.com>

tests/timeseries/mock_resampler.py

@@ -61,7 +61,7 @@ def power_senders(
                 self._input_channels_receivers[name] = [
                     self._channel_registry.get_or_create(
                         Sample[Quantity], name
-                    ).new_receiver()
+                    ).new_receiver(limit=1)
                     for _ in range(namespaces)
                 ]
             return senders