Improve caldav tests to use APIs rather than entity methods (#68745)
Improve caldav tests to use APIs rather than entity methods (#68745)

* Improve caldav tests to use APIs rather than entity methods

Update caldav tests to use the best practice of exercising the public APIs rather than directly calling the entity methods directly. This is motivated by additional calendar API cleanup and possibly future breaking changes.

* Remove unnecessary start/end arguments which are ignored
mezz64/home-assistant,toddeye/home-assistant,toddeye/home-assistant,w1ll1am23/home-assistant,nkgilley/home-assistant,w1ll1am23/home-assistant,mezz64/home-assistant,nkgilley/home-assistant