chore: load next config depends on root publish build directory

Author: rayriffy

helpers/getNextConfig.js

@@ -12,7 +12,7 @@ const getNextConfig = async function (failBuild = defaultFailBuild) {
   const loadConfig = require('next/dist/next-server/server/config').default
 
   try {
-    return await loadConfig(PHASE_PRODUCTION_BUILD, resolve('.'))
+    return await loadConfig(PHASE_PRODUCTION_BUILD, resolve(publishPath))
   } catch (error) {
     return failBuild('Error loading your next.config.js.', { error })
   }