E2E test for Warn about failed jobs in the Project Security Dashboard

Add an E2E test to test the functionality of Warnings about failed jobs in the Project Security Dashboard

gitlab-org/gitlab#208298 (closed)

Steps

1. Log into GitLab
2. Set up a project with relevant security report content
3. Set up CI with a failing job
4. View Project Security Dashboard
5. Ensure that a warning is shown relating to the failed job