Add support for EKS Pod Identity

[ripa1993]

AWS has introduced EKS Pod Identity as a new way for authenticating Kubernetes Pods against AWS APIs.

This requires upgrading the Go AWS SDK to at least 1.23.0, currently 1.16.0 is being used

[voidlily]

It looks like this was partially done in thanos-io/thanos#7335 but I also had trouble getting this to work with pod identity and eventually found this bug report.

[calvinbui]

not working for me either. thought it would after thanos-io/thanos#7157 was closed.

[donovanrost]

Not working for me either

[AagonP]

It's working for me but I need to remove aws_sdk_auth=true ( which default to false).
My s3 config:

type: s3
config:
  bucket: somebucket
  endpoint: s3.us-west-2.amazonaws.com
prefix: someprefix