CHANGELOG entry for PR:3378 (#3747)

Adds an entry to CHANGELOG.next.toml for the
[PR:3378](https://github.com/smithy-lang/smithy-rs/pull/3378

)

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Co-authored-by: Fahad Zubair <fahadzub@amazon.com>
Co-authored-by: david-perez <d@vidp.dev>