Add missing Dependency-Track secret

[ehaldane-digicatapult]

Pull Request

Checklist

• Have you read Digital Catapult's Code of Conduct?
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.

PR Type

• Bug Fix

Linked tickets

ENG-323

High level description

DTRACK_PARENT_GUID: ${{ secrets.DTRACK_PARENT_GUID }} was expected by an upstream change to the shared workflows, but it was never picked up per downstream caller. This has been tested already against digicatapult/hello-world.