Use allow-no-subscriptions for token-only probe

Token-only probe mints an ADO-audience token, which needs no subscription context. Drop subscription-id to avoid a login/subscription-select failure mode; keep client-id and tenant-id as Actions variables.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: MackinnonBuck

.github/workflows/canary-feed-oidc-probe.yml

@@ -21,7 +21,7 @@ jobs:
         with:
           client-id: "${{ vars.CPD_ID_CLIENT_ID }}" # id-cpd-ci
           tenant-id: "${{ vars.CPD_ID_TENANT_ID }}"
-          subscription-id: "${{ vars.CPD_ID_SUBSCRIPTION_ID }}"
+          allow-no-subscriptions: true
 
       - name: Mint Azure DevOps token
         id: adotoken