Remove set-output usage in deploy

See warning: https://github.com/IntelliTect/TestTools.TestFramework/actions/runs/17838335481

Resolution: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

Start by inspecting the deploy workflow associated with the linked Actions run and locate its set-output usage. Read the linked GitHub changelog for the replacement mechanism, then verify the workflow completes without the deprecation warning. Done means deploy no longer uses set-output.

Rédigé par le modèle d'indexation à partir du texte de l'issue.