Bump chai from 4.3.7 to 4.3.9

Bumps [chai](https://github.com/chaijs/chai) from 4.3.7 to 4.3.9.
- [Release notes](https://github.com/chaijs/chai/releases)
- [Changelog](https://github.com/chaijs/chai/blob/4.x.x/History.md)
- [Commits](chaijs/chai@v4.3.7...v4.3.9)

---
updated-dependencies:
- dependency-name: chai
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>