fix: 修复defineOptions使用ObjectMethod语法构建报错

[mackwang112]

当 defineOptions 存在 ObjectMethod 语法构建报错

TypeError: Cannot read properties of undefined (reading 'start')
    at compileScriptSetup (/node_modules/@mpxjs/webpack-plugin/lib/script-setup-compiler/index.js:608:51)

  defineOptions({
    ready() {}, // 报错
    ready: function (){} // 正常
  })