Upgrade the AWS SDK of AWS-related plugins under embulk.org

[dmikurube]

The AWS-related plugins under embulk.org (such as embulk-input-s3) still uses the AWS SDK for Java v1.x, but its v1.x is going to be end-of-support.

https://aws.amazon.com/jp/blogs/developer/announcing-end-of-support-for-aws-sdk-for-java-v1-x-on-december-31-2025/

We need to migrate them to the AWS SDK for Java v2, but it is expected to be a "total rewrite".

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We are looking for a great contributor for this upgrade, which effectively means that we are looking for a new maintainer for the long-term.

If you're interested in it, please let us know in this Discussion at first.