[EKS] [request]: Support dedicated tenancy VPCs

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**Tell us about your request**
What do you want us to build? support for VPC with dedicated tenancy for EKS Clusters

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
We are running in a highly regulated environment. We have a requirement to deploy and implement a specific application on EKS on a special AWS account - where only dedicated tenancy is available.
When running EKS we encounter the following issue:
> **Error: The subnet(s) provided belong to a VPC with unsupported tenancy. Only subnets from VPCs with default tenancy are supported**

**Are you currently working around this issue?**
In principle EKS Anywhere could be used but this is not allowed in highly regulated environments. We need native support.

**How are you currently solving this problem?**
We are not using EKS for critical use cases.

**Additional context**
How to reproduce:

1. Create a vpc with dedicated tenancy with 2 public and 2 private subnets
2. run: `eksctl create cluster --config-file cluster_config.yaml`

expect the error:

> Error: The subnet(s) provided belong to a VPC with unsupported tenancy. Only subnets from VPCs with default tenancy are supported

Content of cluster_config.yaml

```
apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig

metadata:
name: my-test-dedicated
region: us-east-2

vpc:
id: "vpc-xxxxxx"
subnets:
private:
us-east-2b:
id: "subnet-xxxxx"
us-east-2c:
id: "subnet-xxxxx"
public:
us-east-2a:
id: "subnet-xxxxx"
us-east-2b:
id: "subnet-xxxxx"

nodeGroups:
- name: ng-dedicated-vpc
```
Note: the VPC id mentioned in the cluster_config.yaml is of dedicated tenancy type.

Start with the `eksctl create cluster --config-file cluster_config.yaml` entry point and the supplied VPC and subnet configuration. Reproduce the failure using a dedicated-tenancy VPC, then trace how EKS validates VPC tenancy. Done means a cluster can be created from the shown configuration without the unsupported-tenancy error.

Written by the indexing model from the issue text.