avro

Bump rstest from 0.19.0 to 0.20.0 in /lang/rust (#2926)

Bumps [rstest](https://github.com/la10736/rstest) from 0.19.0 to 0.20.0.
- [Release notes](https://github.com/la10736/rstest/releases)
- [Changelog](https://github.com/la10736/rstest/blob/master/CHANGELOG.md)
- [Commits](https://github.com/la10736/rstest/compare/v0.19.0...v0.20.0)

---
updated-dependencies:
- dependency-name: rstest
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>