Moving `aws-sdk` to `devDependencies`?

Hi,

Since the AWS SDK [is available in the AWS Lambda execution environment](https://docs.aws.amazon.com/lambda/latest/dg/current-supported-versions.html), the `aws-sdk` package could be added to `devDependencies` instead, in order to reduce the package size.

What do you think?

Review the package dependency declarations and the AWS Lambda runtime assumptions described in the issue. Confirm whether aws-sdk can be moved to devDependencies without affecting the client’s deployment or local behavior; done means the dependency change is justified and package-size impact is verified.

Written by the indexing model from the issue text.