Need Support for IRSA on AWS

[kartik-moolya]

Is your feature request related to a problem? Please describe.
Currently the AWS signing works only when the request goes through EC2 metadata endpoint. We need to be able to auth using the Webhookidentity auth provided by AWS
https://docs.aws.amazon.com/eks/latest/userguide/iam-roles-for-service-accounts.html

Describe the solution you'd like
Allow creating AWS session object using the webhook identity

Describe alternatives you've considered
Using KIAM or directly the EC2 instance is the only option which cuts down the principle of "least access"

Additional context
This could help us cutting down the dependency on Kiam and rather use native AWS provided kubernetes JWT signing