[Fargate] [request]: Enable EKS Pod Identities on EKS Fargate

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**Tell us about your request**

Please support the new EKS Pod Identities on EKS Fargate.

**Which service(s) is this request for?**

Fargate, EKS

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

We want to replace IAM roles for service accounts (IRSA) and utilize the role session tags introduced by EKS Pod Identity, such as cluster name, namespace, service account name to simplify auditing.

**Are you currently working around this issue?**

We are using IRSA.

**Additional context**

https://docs.aws.amazon.com/eks/latest/userguide/pod-identities.html
https://docs.aws.amazon.com/eks/latest/userguide/service-accounts.html#service-accounts-iam-compare

Start with the EKS Pod Identities and service accounts documentation linked in the issue, then determine how the request relates to EKS Fargate. The issue names no repository files, tests, or entry points; done would mean documented or implemented support for EKS Pod Identities on EKS Fargate.

Written by the indexing model from the issue text.