Bump async from 2.6.0 to 2.6.2
Bump async from 2.6.0 to 2.6.2

Bumps [async](https://github.com/caolan/async) from 2.6.0 to 2.6.2.
- [Release notes](https://github.com/caolan/async/releases)
- [Changelog](https://github.com/caolan/async/blob/v2.6.2/CHANGELOG.md)
- [Commits](https://github.com/caolan/async/compare/v2.6.0...v2.6.2)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
SAP/grunt-openui5,SAP/grunt-openui5