Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 6.7.7 to 9.4.7.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/master/CHANGELOG.md)
- [Commits](https://github.com/postcss/autoprefixer/compare/6.7.7...9.4.7)
Signed-off-by: dependabot[bot] <support@dependabot.com>