Remove "trusted" from the "null-* under every parameterization" terms.
Remove "trusted" from the "null-* under every parameterization" terms.

This undoes bb3c6a6bf620724f58c363c4b93534395935fcca.

I'm not really sure why I liked the idea of "trusted" so much. I don't
really like it now: For any given "world," the type either is or isn't
null-* under every parameterization. The "trusted" term would make more
sense if we weren't already talking about multiple worlds -- that is, if
we were "trusting" that we're in the "right" world. It's not like we
"trust more" in one world than in another.

And this makes the term shorter.

jspecify/jspecify