添加可选链操作符支持 (?. ?: ?[ ?()：支持多返回值，新增 OP_SETTOP 指令，由 BEE_OPTCHAIN 宏启用 - #67

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/