switch to aws-sdk-go-v2

[Benjamin Elder]

As pointed out by @dims in test-infra, the v1 SDK is going away.

The v2 SDK seems a bit differently weird ... I don't see go module compatible tags??

Anyhow, we should migrate.

/kind cleanup
/sig k8s-infra
/priority important-soon

https://aws.amazon.com/blogs/developer/announcing-end-of-support-for-aws-sdk-for-go-v1-on-july-31-2025/

[Davanum Srinivas]

migration guide - https://aws.github.io/aws-sdk-go-v2/docs/migrating/

[Benjamin Elder]

cmd/geranos/s3uploader.go is the only place we actually use the AWS SDK in this repo, so it should be fairly straightforward.

[Benjamin Elder]

fixed in #290