[crag] use non-Nothing inputs in crag toys

Summary: Ben found the everywhere-Nothing inputs a little confusing, and I separately had to provide non-Nothing inputs to reproduce a user issue with to_job and the default IO manager.

Test Plan: bk, run the event_tables job in local dagit

Reviewers: bengotow, cdecarolis

Reviewed By: bengotow

Differential Revision: https://dagster.phacility.com/D9187