feat(spec): update the sdk to the api spec version 2026-01-20

[uibm]

Ran 3982 of 3982 Specs in 109.038 seconds
SUCCESS! -- 3982 Passed | 0 Failed | 0 Pending | 0 Skipped
--- PASS: TestVpcV1 (109.96s)
PASS
ok      github.com/IBM/vpc-go-sdk/vpcv1 111.259s

API Version Update

• Updated default VPC API version from 2025-12-16 to 2026-01-20.

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Instance Availability Class

Added support for instance availability classes, enabling spot instances and explicit preemption behavior.

New Core Models

• InstanceAvailability
• InstanceAvailabilityPatch
• InstanceAvailabilityPrototype

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Availability Policy Enhancements

Extended instance availability policy to model spot preemption behavior.

Updated / Extended Models

• InstanceAvailabilityPolicy
• InstanceAvailabilityPolicyPatch
• InstanceAvailabilityPolicyPrototype

New Capability

• Added preemption action:
  • delete
  • stop

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Instance, Prototype & Template Updates

Added explicit availability support across all instance surfaces.

Updated Structs

• Instance (availability required in responses)
• InstancePatch
• InstancePrototype
• InstanceTemplate
• InstanceTemplatePrototype
• All InstanceBy* and instance-template context structs

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Instance Profile Enhancements

Extended instance profiles to declare availability-class constraints.

New Profile Models

• InstanceProfileAvailabilityClass
• InstanceProfileAvailabilityClassEnum
• InstanceProfileAvailabilityClassFixed

Updated Struct

• InstanceProfile
  • Added required AvailabilityClass

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Instance Listing & Filtering

New Filter

• availability.class (spot, standard) added to ListInstancesOptions

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Lifecycle & Status Updates

• Added new instance status reason:
  • stopped_by_preemption

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