ci: add dependency scanning
We are working to add Dependency Scanning to projects that are either part of or related to the GitLab product. This MR adds a CI configuration file and includes Dependency Scanning as part of its work.
It should be noted that Dependency Scanning only has full support for basic CI pipelines at this time. Support for Merge Request pipelines is an item on the roadmap, meaning Dependency Scanning may only run on this project against its default branch.