New validation for Microsoft subscription upgrades when a quantity change is pending

^{Minor Upgrade}

This update turns on a new validation so that a Microsoft subscription upgrade or plan/SKU change can be temporarily blocked while Microsoft still has a pending quantity-related scheduled change on that subscription. When validation applies, customers see a message that the upgrade is temporarily blocked because a quantity change is still pending with Microsoft. They can retry after that change completes.

📝 Note: This behavior aligns the US Cluster with other cluster regions, where the same validation already applies.

Feature enablement

This feature is enabled by default.

Setting enablement

No setting enablement is required.

Documentation

No documentation updates are required.