Packaging Pipeline: fail fast if both `WINDOWS_PACKAGE_ENABLED` and `ONLY_PROMOTION` parameters are selected

[dduportal]

From jenkins-infra/helpdesk#4774 (comment)

This feature request comes from a feedback about the new staging made during the 2025-12-10 security advisory.

It would help operator to quickly catch an error in intent as no one expect "promotion only" with Windows.