run tests before finalizing draft release

Currently, `cargo dist` would publish a release that has failing tests. I think it would be good to run `cargo test` before uploading artifacts for a release. This could be done either in the CI script or integrated into the `cargo dist build` command... or maybe as a `cargo dist test` command?

Start by reviewing the existing cargo dist build flow and the CI script, then run cargo test to understand the required release check. The open design question is whether testing belongs in CI, cargo dist build, or a new cargo dist test command; done means failing tests cannot reach artifact upload.

Written by the indexing model from the issue text.