Assess the impact of Hashicorp license changes from MPL to BSL

[upodroid]

Hashicorp is changing their licenses and we use their deps in knative.

https://www.hashicorp.com/license-faq

The APIs & SDKs will still be licensed under MPL but it still warrants a careful considation.

https://github.com/search?type=code&q=org%3Aknative+OR+org%3Aknative-extensions+hashicorp&p=3

Current libraries that are used:

• github.com/hashicorp/golang-lru
• github.com/hashicorp/hcl
• github.com/hashicorp/go-multierror
• github.com/hashicorp/go-cleanhttp
• github.com/hashicorp/errwrap
• github.com/hashicorp/go-retryablehttp
• github.com/hashicorp/go-version
• github.com/hashicorp/go-rootcerts
• github.com/hashicorp/go-sockaddr
• github.com/hashicorp/go-plugin

CNCF issue: https://github.com/cncf/foundation/issues/617