Update canary runner in aws-sdk-rust repo to point at canary code from latest release tag

[landonxjames]

Currently the canary in the aws-sdk-rust repo is failing every daily run (example). This is a side effect of merging #4006 which updated the canary's presigned S3 request logic to more thoroughly check headers so it would catch similar bugs in the future. The canary run in aws-sdk-rust pulls the canary code from the HEAD of the smithy-rs repo and runs it against the version of the SDK currently published in aws-sdk-rust. Since the canary was updated to catch a bug, but the codegen change fixing that bug has not yet been released the canary is failing every time.

To fix this we likely want to pin the version of the canary code that runs to the most recent release tag in smithy-rs so the canary code is aligned with the generated code in aws-sdk-rust