Update Auto DevOps to use the reports syntax for Dependency Scanning

Problem to solve

We want Dependency Scanning in Auto DevOps to provide results to the Group Security Dashboard.

This means that we need to update the template with the new syntax.

Further details

See https://gitlab.com/gitlab-org/gitlab-ce/issues/54160 for more details.

Proposal

Replace the existing code

  artifacts:
    paths: [gl-dependency-scanning-report.json]

With this new one

  artifacts:
    reports:
      dependency_scanning: gl-dependency-scanning-report.json