aks: Release 2026-01-04

AKS release 2026-01-04: Ubuntu 24.04 becomes the default OS SKU starting Kubernetes v1.35; multiple OS/node image updates and security/component upgrades; deprecations and retirements announced (Ubuntu 18.04 removed, Azure Linux 2.0 end-of-support and removal, Basic Load Balancer retired, Kubernetes 1.31 deprecated); several new previews and behavioral changes; important dates and migration actions required.

• Source: Release notes from AKS