Hierarchical Reservation Groups and Flex Plan Deprecation

A new patch method is now available for reservationGroups, allowing for updates to existing resources via projects.locations.reservationGroups.patch. The ReservationGroup schema has been extended with a parentGroup field, enabling the creation of hierarchical reservation structures. Concurrently, the FLEX commitment plan has been marked as deprecated in both the plan and renewalPlan fields of the CapacityCommitment schema, with guidance to transition to Edition-based capacity commitments.