Fix pipelines on dev

Our dev instance is running GitLab CE, it does not include Ultimate licensed security features.

Every included template should use the full path "Security/Template-Name.gitlab-ci.yml" to be safely ignored on that instance.

Otherwise, we get errors like the following

   Pipeline cannot be run.
   Included file `Dependency-Scanning.gitlab-ci.yml` is empty or does not exist!

Related to: gitlab-com/gl-infra/delivery#1726 (closed)