#22749 broke release unit tests by not providing a legacy key - that key should be optional because we will b dealing with non-legacy tests soon.
Additionally, for some reason the unit tests pass on buildkite while they fail locally and in the release test pipeline. I'm investigating this now...
Of all smoke test arguments, frequency is the only required one, so we should check for it. Additionally, not all fields should be able to be overwritten (e.g. legacy or name), so we enforce this as well.
This currently leads to failing builds for schema validation errors after #22901 was merged (the stable column was incorrectly not added to the schema before).
To avoid breakage like in #22905, this PR adds schema validation to the release test package.
In a follow-up PR, we'll likely switch this to use pydantic instead.
