Add SCANOSS Action

[jeffpaul]

Description of the Change

This adds the SCANOSS.com license scanning action to check our repo to ensure all dependencies are using approved licensing. Will continue testing this as a draft PR until validated to work as expected at which point will look to replicate across our projects.

If this gets merged in, then we'll want to close #122 as no longer needed.

Alternate Designs

Cross our fingers and hope that we will catch invalid licensed dependencies on our own

Possible Drawbacks

Until we fine-tune this action, we may get a lot of false positives (but hopefully after some testing this will be relatively quiet until something non-GPL-compatible is mistakenly added in a PR).

Verification Process

Reviewed docs for the GH Action, will see how it performs once this PR is opened and we can view the results of its check.

Checklist:

• [x] I have read the CONTRIBUTING document.
• [ ] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [ ] I have added tests to cover my change.
• [ ] All new and existing tests passed.

Changelog Entry

Added - Scanning of dependencies to ensure they are GPL-compatible.

Credits

Props @jeffpaul, @vikrampm1.