feat: add EKS Hybrid Nodes support

[sanbyk]

Issue

#4315

Description

This PR adds support for pods running on EKS Hybrid Nodes (on-premise). These nodes have no EC2 instance or VPC ENI and previously caused reconciliation failures when resolving pod endpoints and node instance IDs. The controller now detects hybrid nodes/pods, skips EC2-/ENI-specific logic, and reconciles TargetGroupBindings for hybrid endpoints.

Changes

Hybrid nodes detection

• Update ExtractNodeInstanceID to recognize eks-hybrid ProviderID
• Return a clearly non-EC2 instance identifier (special prefix) to:
  • Avoid accidental DescribeInstances calls
  • Keep a stable, non-empty key for logging/maps/metrics

Pod ENI resolution

• Extend pod classification to include hybrid using eks.amazonaws.com/compute-type=hybrid
• Skip ENI lookups entirely for hybrid pods; return placeholder ENI info to mark “no ENI”

Networking reconciliation

• Skip backend Security Group resolution/management for hybrid endpoints, since there are no ENIs/SGs to manage

Node instance fetch

• Exclude hybrid nodes from EC2 DescribeInstances fan-out in NodeInfoProvider

Tests

• Add hybrid nodes focused unit tests for classification and resolution
• Extend node instance ID extraction tests to cover eks-hybrid providerIDs

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the docs directory)
• Manually tested
• Made sure the title of the PR is a good description that can go into the release notes

BONUS POINTS checklist: complete for good vibes and maybe prizes?! 🤯

• Backfilled missing tests for code in same general area 🎉
• Refactored something and made the world a better place 🌟

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[shraddhabang]

/ok-to-test

[malodie]

Bump. We're waiting on this feature to move forward with hybrid nodes, as the aws-load-balancer-controller is the documented way (by AWS) to do ingress. It appears to work when we provision pods first on EC2, but then falls apart when the pods return to the hybrid state. I am also happy to test this in my working lab cluster once it releases (or before, if necessary).