Remove print(key) that leaks secret value to pipeline logs

[Manya Sharma (ManyaS-Git)]

Summary

.ci/scripts/set_secret.py prints the raw value of storage_conn_string (line 33: print(key)) to stdout before storing it in Azure Key Vault. Because the script is invoked by .ci/steps/deploy_steps.yml:65 and .ci/steps/deploy_steps_v2.yml:77, the secret value is captured in the Azure DevOps pipeline build log — visible to anyone with access to the run.

The print() is debug output; the function's own return message (print(message) on line 36) already confirms success. Removing the single line eliminates the leak with no change to the script's function.

Verification

• Script syntax validated with py_compile.
• The only callers pass -n <key-name> via the inline script in deploy_steps.yml; the removed line is standalone with no downstream dependency.
• Bug confirmed present on upstream microsoft/AI master.