refactor: avoid exposing other utils

Author: danielroe

src/e2e.ts

@@ -5,5 +5,5 @@ export * from './core/nuxt'
 export * from './core/server'
 export * from './core/setup/index'
 export * from './core/run'
-export * from './core/runtime-config'
+export { setRuntimeConfig } from './core/runtime-config'
 export * from './core/types'