Bump train-core from 3.1.8 to 3.2.0 in /omnibus
Bump train-core from 3.1.8 to 3.2.0 in /omnibus

Bumps [train-core](https://github.com/inspec/train) from 3.1.8 to 3.2.0.
- [Release notes](https://github.com/inspec/train/releases)
- [Changelog](https://github.com/inspec/train/blob/master/CHANGELOG.md)
- [Commits](https://github.com/inspec/train/compare/v3.1.8...v3.2.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
chef/chef-dk,chef/chef-dk,chef/chef-dk