Remove updates field and schemas from CreateDegradation/Maintenance requests; add last_modified_by_user_uuid

BreakingBreaking change

This is a breaking change — integrations that rely on the affected behaviour will need updates before the change rolls out.

What changed

Two breaking removals and one additive change:

The updates field (an array) has been removed from CreateDegradationRequestDataAttributes and CreateMaintenanceRequestDataAttributes request bodies. Clients that were sending updates in these payloads will silently lose that data or receive errors.
The schemas CreateDegradationRequestDataAttributesUpdatesItems, CreateDegradationRequestDataAttributesUpdatesItemsComponentsAffectedItems, CreateMaintenanceRequestDataAttributesUpdatesItems, and CreateMaintenanceRequestDataAttributesUpdatesItemsComponentsAffectedItems have been entirely deleted from the spec.
A new optional response field last_modified_by_user_uuid (UUID of the last modifying user) has been added to an update-related schema.