Use a `rustv1` directory from `aws-doc-sdk-examples` (#3287)

## Motivation and Context
This PR is a cleanup after
https://github.com/smithy-lang/smithy-rs/pull/3115, fully switching to
`rustv1` for the rust example directory in
[aws-doc-sdk-examples](https://github.com/awsdocs/aws-doc-sdk-examples).

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