[Feature] Megatron支持CHORD训练

[llan-ml]

Checklist / 检查清单

• I have searched existing issues, and this is a new feature request. / 我已经搜索过现有的 issues，确认这是一个新的 Feature Request。

Feature Request Description / Feature Request 描述

Megatron中GRPO训练不支持CHORD模式，求大佬适配

Pull Request / Pull Request 信息

No response