Vouch Request: fix Bun runtime detection bug (#3105)

[abhay0132]

Why do you want to contribute?

Hi! I'd love to contribute to trigger.dev.

I've already opened a PR fixing issue #3105 — the deployment UI
showing "Node.js" when Bun is actually being used.

PR: #3239

The fix is in packages/cli-v3/src/config.ts — instead of hardcoding
"node" as the default runtime, I added auto-detection via
process.versions.bun so the correct runtime is picked up even when
not explicitly set in trigger.config.ts.

Background: I'm a backend engineer (Node.js/TypeScript/PostgreSQL),
final year CS student, completed a production API internship at STPI
(Govt. of India). Looking to contribute consistently to trigger.dev
going forward.

Prior contributions or relevant experience

No response