As suggested above, I've prepared a PR that moves CalciteAssert, Matchers, and a couple of test schemata to the new :testkit module.
calcite-*-tests.jar will no longer be published. PR: https://github.com/apache/calcite/pull/2558 The tests pass, and the change unlocks migration to Gradle 7.2 and Java 17 (the migration is included in PR#2558). I'm going to merge the PR soon. Vladimir
