Support EKS Pod Identity

[richardcase]

/kind feature

Describe the solution you'd like

Add support for EKS Pod Identity to CAPA for EKS clusters. This will be an alternative to IRSA and is simpler as it doesn't require creation of OIDC providers

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]

Environment:

• Cluster-api-provider-aws version:
• Kubernetes version: (use kubectl version):
• OS (e.g. from /etc/os-release):

[richardcase]

/priority important-shorterm
/triage accepted
/area provider/eks

[k8s-ci-robot]

@richardcase: The label(s) priority/important-shorterm cannot be applied, because the repository doesn't have them.

In response to this:

/priority important-shorterm
/triage accepted
/area provider/eks

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[richardcase]

/priority important-soon