[EKS] [request]: Allow Auto Mode TargetGroupBinding to update target groups in other VPCs

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**Tell us about your request**

**Which service(s) is this request for?**
EKS Auto Mode

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**

Like #2508, this is related to using `TargetGroupBinding`s to register in-cluster targets to be used by an external load balancer; the reasons for which are explained well in the linked issue.

In my case, I have all my ingress resources, including load balancers, in a separate VPC. To be able to direct traffic to EKS targets from there, the target group must be in the same VPC, and the TargetGroupBinding must be able to add its targets to it.

I have an existing cluster with Load Balancer Controller installed using the [Helm chart](https://github.com/aws/eks-charts/tree/master/stable/aws-load-balancer-controller) (`vpcId` configuration value set to the ingress VPC ID - this doesn't seem to be used for anything any more) where this works fine. The [documentation](https://kubernetes-sigs.github.io/aws-load-balancer-controller/latest/guide/targetgroupbinding/targetgroupbinding/#vpcid) mentions a `vpcID` value in the CRD, but this is not part of the Auto Mode CRD `targetgroupbindings.eks.amazonaws.com`.

When trying to register targets on a target group in a different VPC, the following message appears in CloudTrail:

> You must specify a valid Availability Zone or select 'all' for all enabled Availability zones, since the IP address '10.x.x.x' is outside the VPC

**Are you currently working around this issue?**
No

**Attachments**

[CloudTrail event](https://github.com/user-attachments/files/24258001/ct.json)

Start with linked issue #2508 and the TargetGroupBinding vpcID documentation and Auto Mode CRD references. Inspect the attached CloudTrail event to confirm the current cross-VPC failure. Done means Auto Mode TargetGroupBinding can register targets in a target group from another VPC.

Written by the indexing model from the issue text.