Bump async and htmlhint

Bumps [async](https://github.com/caolan/async) to 2.6.4 and updates ancestor dependency [htmlhint](https://github.com/htmlhint/HTMLHint). These dependencies need to be updated together.


Updates `async` from 2.6.3 to 2.6.4
- [Release notes](https://github.com/caolan/async/releases)
- [Changelog](https://github.com/caolan/async/blob/v2.6.4/CHANGELOG.md)
- [Commits](caolan/async@v2.6.3...v2.6.4)

Updates `htmlhint` from 0.10.1 to 1.1.4
- [Release notes](https://github.com/htmlhint/HTMLHint/releases)
- [Changelog](https://github.com/htmlhint/HTMLHint/blob/master/CHANGELOG.md)
- [Commits](htmlhint/HTMLHint@0.10.1...v1.1.4)

---
updated-dependencies:
- dependency-name: async
  dependency-type: indirect
- dependency-name: htmlhint
  dependency-type: direct:development
...

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