test: fix flaky mqtt adapter tests with events

The `test_standalone/test_mqtt_adapter.py` test suite used `await asyncio.sleep(0.02)` to wait for mocked methods to be called before assertions. Under higher load, or in some configurations like Python 3.13, this constant delay was insufficient, causing intermittent failures such as `AssertionError: Expected 'publish_log' to have been called`. This replaces the arbitrary sleeps with deterministic synchronization primitives (`asyncio.Event`) where tests wait explicitly for up to 1 second for the mocked function to be called before checking assertions.

Also run `black` to format the new code modifications.

Co-authored-by: rnovatorov <20299819+rnovatorov@users.noreply.github.com>

Author: google-labs-jules[bot]

tests/unit/test_standalone/test_mqtt_adapter.py

@@ -126,9 +126,11 @@ async def test_publish_properties_exception():
     mqtt_api_client = mock.AsyncMock(spec=enapter.mqtt.api.Client)
     device_channel = mock.AsyncMock(spec=enapter.mqtt.api.device.Channel)
     event = asyncio.Event()
+
     def publish_properties_mock(*args, **kwargs):
         event.set()
         raise RuntimeError("Publish error")
+
     device_channel.publish_properties.side_effect = publish_properties_mock
     mqtt_api_client.device_channel.return_value = device_channel
     async with asyncio.TaskGroup() as tg:
@@ -148,9 +150,11 @@ async def test_publish_telemetry_exception():
     mqtt_api_client = mock.AsyncMock(spec=enapter.mqtt.api.Client)
     device_channel = mock.AsyncMock(spec=enapter.mqtt.api.device.Channel)
     event = asyncio.Event()
+
     def publish_telemetry_mock(*args, **kwargs):
         event.set()
         raise RuntimeError("Publish error")
+
     device_channel.publish_telemetry.side_effect = publish_telemetry_mock
     mqtt_api_client.device_channel.return_value = device_channel
     async with asyncio.TaskGroup() as tg:
@@ -170,9 +174,11 @@ async def test_publish_logs_exception():
     mqtt_api_client = mock.AsyncMock(spec=enapter.mqtt.api.Client)
     device_channel = mock.AsyncMock(spec=enapter.mqtt.api.device.Channel)
     event = asyncio.Event()
+
     def publish_log_mock(*args, **kwargs):
         event.set()
         raise RuntimeError("Publish error")
+
     device_channel.publish_log.side_effect = publish_log_mock
     mqtt_api_client.device_channel.return_value = device_channel
     async with asyncio.TaskGroup() as tg: