Update mqtt_eventstream tests to pytest style functions (#42119)

tests/components/mqtt_eventstream/test_init.py

@@ -1,8 +1,6 @@
 """The tests for the MQTT eventstream component."""
 import json
 
-import pytest
-
 import homeassistant.components.mqtt_eventstream as eventstream
 from homeassistant.const import EVENT_STATE_CHANGED
 from homeassistant.core import State, callback
@@ -18,11 +16,6 @@ from tests.common import (
 )
 
 
-@pytest.fixture(autouse=True)
-def mock_storage(hass_storage):
-    """Autouse hass_storage for the TestCase tests."""
-
-
 async def add_eventstream(hass, sub_topic=None, pub_topic=None, ignore_event=None):
     """Add a mqtt_eventstream component."""
     config = {}