Make oxc packages ESM-only

Hey all 👋 

Right now, JS packages like `oxc-minify` or `oxc-parser` are CJS-only.
Given that Vite is ESM-only already, we should move also in that direction and publish all packages as ESM-only too.

Related: https://github.com/antfu/node-modules-inspector/issues/124