Add Dependency Scanning

We are seeking to turn on Dependency Scanning for all projects which are part of the GitLab product. This MR adds the feature to this project's CI.

As this project utilizes a form of merge request pipelines, Dependency Scanning should only run after merge on the default branch.

Related issues

• https://gitlab.com/gitlab-org/gitlab/-/issues/349644
• https://gitlab.com/groups/gitlab-org/-/epics/7322