[EKS] [request]: Support Cilium as CNI for hosted EKS

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Currently, Cilium requires chaining or removing the aws-node daemonset and restarting all pods that were created with old CNI.
EKS Anywhere now uses Cilium as the CNI by default.
It would be great if new clusters could be provisioned with an optional configuration option to use Cilium, or if Cilium were provided as a managed add-on with a documented/automated migration process.

Start by reviewing how hosted EKS clusters provision the aws-node daemonset and how CNI choices are configured. Compare the requested alternatives: an optional Cilium configuration versus a managed add-on with documented or automated migration. Done would mean a defined implementation path that supports new clusters and addresses existing pods and CNI migration.

Written by the indexing model from the issue text.