Upgrade to Smithy 1.59 (#4185)

## Motivation and Context
<!--- Why is this change required? What problem does it solve? -->
<!--- If it fixes an open issue, please link to the issue here -->

Needed to bump our Smithy version to enable the work in
https://github.com/smithy-lang/smithy-rs/pull/4186.

## Description
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Various changes, mostly to protocol tests, to align with the new Smithy
version. Discovered https://github.com/smithy-lang/smithy-rs/issues/4184


while working on this, which is a deeper bug that will be fixed in a
separate PR.

## Testing
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to -->
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## Checklist
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- [ ] For changes to the smithy-rs codegen or runtime crates, I have
created a changelog entry Markdown file in the `.changelog` directory,
specifying "client," "server," or both in the `applies_to` key.
- [ ] For changes to the AWS SDK, generated SDK code, or SDK runtime
crates, I have created a changelog entry Markdown file in the
`.changelog` directory, specifying "aws-sdk-rust" in the `applies_to`
key.

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Co-authored-by: ysaito1001 <awsaito@amazon.com>