[light] Type-annotate to_code in mock_addressable_light

tests/integration/fixtures/external_components/mock_addressable_light/light.py

@@ -2,6 +2,7 @@ import esphome.codegen as cg
 from esphome.components import light
 import esphome.config_validation as cv
 from esphome.const import CONF_NUM_LEDS, CONF_OUTPUT_ID
+from esphome.types import ConfigType
 
 mock_addressable_light_ns = cg.esphome_ns.namespace("mock_addressable_light")
 MockAddressableLight = mock_addressable_light_ns.class_(
@@ -16,7 +17,7 @@ CONFIG_SCHEMA = light.ADDRESSABLE_LIGHT_SCHEMA.extend(
 )
 
 
-async def to_code(config):
+async def to_code(config: ConfigType) -> None:
     var = cg.new_Pvariable(config[CONF_OUTPUT_ID], config[CONF_NUM_LEDS])
     await light.register_light(var, config)
     await cg.register_component(var, config)