Convert image_processing tests to pytest (#56451)
Convert image_processing tests to pytest (#56451)

* Convert image_processing tests to pytest

* Use existing fixtures and test helpers

* Remove useless code
home-assistant/home-assistant,home-assistant/home-assistant,rohitranjan1991/home-assistant,aronsky/home-assistant,rohitranjan1991/home-assistant,GenericStudent/home-assistant,w1ll1am23/home-assistant,rohitranjan1991/home-assistant,GenericStudent/home-assistant,toddeye/home-assistant,mezz64/home-assistant,w1ll1am23/home-assistant,mezz64/home-assistant,jawilson/home-assistant,nkgilley/home-assistant,aronsky/home-assistant,jawilson/home-assistant,lukas-hetzenecker/home-assistant,lukas-hetzenecker/home-assistant,toddeye/home-assistant,nkgilley/home-assistant