Update parallel requirement from < 1.20 to < 1.21
Update parallel requirement from < 1.20 to < 1.21

Updates the requirements on [parallel](https://github.com/grosser/parallel) to permit the latest version.
- [Release notes](https://github.com/grosser/parallel/releases)
- [Commits](https://github.com/grosser/parallel/compare/v0.1.0...v1.20.1)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
chef/appbundle-updater,chef/appbundle-updater