[megatron] update cross_entropy_fusion_impl default value 'te' -> 'native' (#9578) - #9578

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v3. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/