Upgrade to AWS SDK Go v2

The maintainers of AWS SDK for Go launched v2 recently (in its own repository/Go mod) to leverage Go modules. A number of packages provided by the SDK have been modularized and are independently versioned and released respectively. This change enables improved application dependency modeling, and enables the SDK to provide new features and functionality that follows the Go module versioning strategy.

The release process currently uses the AWS SDK Go v1 for services like session creation, S3, ECR and ECR Public clients etc. We should follow the [migration guide](https://aws.github.io/aws-sdk-go-v2/docs/migrating/) to upgrade our dependencies to aws-sdk-go-v2.

Start with the release process that currently uses AWS SDK Go v1 for session creation, S3, ECR, and ECR Public clients. Read the linked AWS SDK Go v2 migration guide and identify all affected dependencies and call sites. Done means those release-process integrations use independently versioned aws-sdk-go-v2 modules and continue to provide the same functionality.

Written by the indexing model from the issue text.