Bump eslint-config-prettier from 6.7.0 to 6.9.0

Bumps [eslint-config-prettier](https://github.com/prettier/eslint-config-prettier) from 6.7.0 to 6.9.0.
- [Release notes](https://github.com/prettier/eslint-config-prettier/releases)
- [Changelog](https://github.com/prettier/eslint-config-prettier/blob/master/CHANGELOG.md)
- [Commits](https://github.com/prettier/eslint-config-prettier/commits/v6.9.0)

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