fix: fix undefined error for accessing lang of script

Author: freedomlang

lib/index.js

@@ -117,7 +117,7 @@ module.exports = function (source) {
   // let isTS = false
   const { script, scriptSetup } = descriptor
   if (script || scriptSetup) {
-    const lang = script.lang || (scriptSetup && scriptSetup.lang)
+    const lang = script?.lang || scriptSetup?.lang
     // isTS = !!(lang && /tsx?/.test(lang))
     const externalQuery =
       script && !scriptSetup && script.src ? `&external` : ``