Changes cast-lossless to a pedantic lint
As discussed in #4528, this moves the cast-lossless lint from `all` to `pedantic`.
I couldn't tell from description alone if it should also be removed from the complexity category, so I left it as part of complexity for now. I didn't see any impact to the tests from this change, but I could be wrong (as this is my first PR).
fixes#4528
changelog: Moves cast-lossless from default to checking only as a `pedantic` lint.
f08f171530