[CI] Track Dependencies

[michael-hawker]

Describe the problem this feature would solve

There's a new Dependency Review service coming for GitHub: github/roadmap#80

As announced: https://github.blog/2020-12-08-new-from-universe-2020-dark-mode-github-sponsors-for-companies-and-more/

Describe the solution

We should adopt this for our PRs to ensure we know when dependencies are added/changed.

Describe alternatives you've considered

NDepend #3576

Hello, 'michael-hawker! Thanks for submitting a new feature request. I've automatically added a vote 👍 reaction to help get things started. Other community members can vote to help us prioritize this feature in the future!