[smoke-test] fix send slack notification (#16887)

Author: iQQBot

.github/workflows/preview-env-check-regressions.yml

@@ -123,11 +123,13 @@ jobs:
                   paths: "test/tests/**/TEST.xml"
               if: always()
             - id: auth
+              if: failure()
               uses: google-github-actions/auth@v1
               with:
                   token_format: access_token
                   credentials_json: "${{ secrets.GCP_CREDENTIALS }}"
             - name: Get Secrets from GCP
+              if: failure()
               id: 'secrets'
               uses: 'google-github-actions/get-secretmanager-secrets@v1'
               with: