Course completion/cert request workflow may fail when submitter did not complete requirements

[afewell]

Found a case where member did not complete one of the 3 required tests for vSphere with Tanzu 101 course before requesting certificate of completion. The cert completion workflow failed rather than properly recognizing the missing condition. The workflow should properly handle this error and report a useful message back to the requestor about what they missed.

Here is the action reference for the failure scenario:
https://github.com/ModernAppsNinja/vspheretanzu101_vt7301/runs/2734892527