Include `engines` field in `package.json`?

[MaoShizhong]

The repo currently does not specify which version of Node the bot is deployed on, so there is a chance that code runs locally but breaks in prod if it's running on a version that doesn't have a newer feature.

Recently, I had a PR that Fred reviewed that broke with one commit because I unknowingly used a Node v22+ feature and he was still on v20. Finding out what version the bot is deployed on (if available, able to bump it to the latest host version?) then setting that as the max in package.json would help prevent any such bugs.

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Edit: Accidentally created a blank issue. Happy to add this in if we can found out the exact version the bot is deployed on.