Fix automation in packages (#43202)

homeassistant/components/automation/__init__.py

@@ -52,6 +52,8 @@ from homeassistant.helpers.typing import TemplateVarsType
 from homeassistant.loader import bind_hass
 from homeassistant.util.dt import parse_datetime
 
+# Not used except by packages to check config structure
+from .config import PLATFORM_SCHEMA  # noqa
 from .config import async_validate_config_item
 from .const import (
     CONF_ACTION,