Guard support-label workflows when SUPPORT_LABELS_TOKEN is unavailable

[Copilot]

The audit Actions job was failing before it could perform any checks because SUPPORT_LABELS_TOKEN was unset, leaving GH_TOKEN empty. This change makes the support-label workflows degrade cleanly when the token is not configured.

• Workflow gating

  • Promote SUPPORT_LABELS_TOKEN to a job-level env in both support-label workflows.
  • Skip token-dependent steps unless the secret is present.

• Graceful no-op behavior

  • Add an explicit notice step so skipped runs are visible in Actions output instead of failing inside the shell script.
  • Preserve existing behavior unchanged when the token is configured.

• Scope

  • Apply the same guard to both:
    • audit-support-labels.yml
    • apply-support-labels.yml

env:
  SUPPORT_LABELS_TOKEN: ${{ secrets.SUPPORT_LABELS_TOKEN }}

- name: Skip audit when support-labels token is unavailable
  if: ${{ env.SUPPORT_LABELS_TOKEN == '' }}
  run: echo "::notice::SUPPORT_LABELS_TOKEN is not configured; skipping support-label audit."

- name: Audit support labels
  if: ${{ env.SUPPORT_LABELS_TOKEN != '' }}
  env:
    GH_TOKEN: ${{ env.SUPPORT_LABELS_TOKEN }}