chore(deps): bump browserslist from 4.16.4 to 4.16.6 in /test

Bumps [browserslist](https://github.com/browserslist/browserslist) from 4.16.4 to 4.16.6.
- [Release notes](https://github.com/browserslist/browserslist/releases)
- [Changelog](https://github.com/browserslist/browserslist/blob/main/CHANGELOG.md)
- [Commits](https://github.com/browserslist/browserslist/compare/4.16.4...4.16.6)

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