Add "bun" export condition to common export conditions

[jcbhmr]

I need to change my commit message because I read https://github.com/nodejs/node/blob/HEAD/doc/contributing/pull-requests.md#commit-message-guidelines after making the tiny change 🤣

For reference on the "bun" export condition: https://bun.sh/docs/runtime/modules#resolution

[nodejs-github-bot]

Review requested:

• @nodejs/loaders
• @nodejs/modules

[guybedford]

Rather than expanding this section to every platform, it may be better at this point to reference the list at https://runtime-keys.proposal.wintercg.org/ directly here.

[jcbhmr]

Good point! Though I note that https://runtime-keys.proposal.wintercg.org/ doesn't include the "types" condition which the Node.js docs do. It also doesn't include "browser", "development" or "production". Maybe it would be best to keep only Node.js-ish stuff like this (below)?

• "types"
• "browser"
• "react-native"
• "development"
• "production"

note the lack of "deno" and "bun"
and then a link to the https://runtime-keys.proposal.wintercg.org/ ?

[guybedford]

That sounds sensible to me - now that these keys have a definition elsewhere, it would make sense to avoid duplication for them.