Silence deprecate in tests

With all the inconsistent deprecation silencers cleaned up, there is a bunch of noise during test runs. As a quick fix, we can just overwrite deprecate to be quieter.

![](https://api.monosnap.com/image/download?id=Oeeb8pEUmHAO39uBuYphcpQf6)

Note that this keeps the `Ember.ENV.RAISE_ON_DEPRECATION` check- that is needed for one test in Ember doing a negative assertion on deprecations.

I think we can build a better solution shortly.