Merge pull request #2346 from esphome/bump-2021.9.1

esphome/components/api/api_connection.cpp

esphome/components/api/api_frame_helper.cpp

esphome/components/api/api_frame_helper.h

esphome/components/cover/automation.h

esphome/components/demo/demo_sensor.h

esphome/components/light/addressable_light.cpp

esphome/components/light/addressable_light.h

esphome/components/light/addressable_light_effect.h

esphome/components/light/light_state.cpp

esphome/components/light/transformers.h

esphome/components/mqtt/mqtt_sensor.cpp

esphome/components/sensor/filter.cpp

esphome/components/sensor/filter.h

esphome/components/sensor/sensor.cpp

esphome/components/sensor/sensor.h

esphome/components/socket/bsd_sockets_impl.cpp

esphome/components/socket/headers.h

esphome/components/socket/lwip_raw_tcp_impl.cpp

esphome/components/socket/socket.h

esphome/const.py