chore(beep boop 🤖): Bump `MCORE_TAG=2f67f35...` (2024-12-05)
🚀 PR to bump `NVIDIA/Megatron-LM` in `Dockerfile.ci` to `MCORE_TAG=2f67f35b4a9e5596034e93eddeed07009bcf630c`.  

📝 Please remember the following to-do's before merge: 
- [ ] Verify the presubmit CI  

🙏 Please merge this PR only if the CI workflow completed successfully.