Inject NODE_ENV with production value by default for production runtime

[pi0]

Ref nuxt/nuxt#23402

While nitro externals tracer rewrites exports conditions to production (#844), in runtime of some externals there are still manual check for NODE_ENV. (hopefully, some day they use exports conditions with production support to remove need of this)

This is an alternative of previously PR #605 to inject only at runtime which is our more specific concern also works for all node runtimes without depending on commands