chore: add `async_rest` extra for async rest dependencies (#701)

* fix: add extra for aiohttp

* improve error message

* with -> w; apply same change to prerelease_deps

* move error to try block

* address feedback

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* update noxfile

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Co-authored-by: ohmayr <omairnaveed@ymail.com>
Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
7 files changed