Support IAM roles for service accounts

[dudicoco]

The new feature which supports assigning IAM roles directly to pods was recently released:
https://aws.amazon.com/blogs/opensource/introducing-fine-grained-iam-roles-service-accounts/

Currently, the kubernetes-external-secrets pod is not able to assume the role and is using the node assigned role instead, although the aws-sdk version in nodejs supports the new feature.

[Flydiverny]

@dudicoco Have you checked all the kinks in the previous issue? #164

[dudicoco]

@Flydiverny I have now checked all of the related issues.
Everything seems to be configured properly on my side, but I am experiending the same issue as url

[Flydiverny]

Somehow I managed to link to the wrong issue was meant to refer to #161

I haven't tested this myself but my understanding is that if kiam or something else provides credentials to the pod, these are used before the IRSA credentials.

As seen here:
https://github.com/aws/aws-sdk-js/blob/v2.575.0/lib/node_loader.js#L61-L69

Please verify that you are not using other means of providing AWS credentials to the pod that have higher priority than TokenFileWebIdentityCredentials which should be what is used for IRSA

[Flydiverny]

Closing this as it seems resolved by discussion in #200