Bump @types/chai from 4.3.6 to 4.3.8

Bumps [@types/chai](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/chai) from 4.3.6 to 4.3.8.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/chai)

---
updated-dependencies:
- dependency-name: "@types/chai"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>