[Draft] Update Megatron submodule pins

[yaoyu-33]

No description provided.

[github-actions]

❌ Submodule Fast-Forward Check Failed

Check based on commit: 2712979 (PR #1787 from update-megatron-lm-5247a1f)

✅ Submodules that are properly updated:

Megatron-Bridge: ✅ PR branch is ahead of main branch (fast-forward)

❌ Submodules that need attention:

Megatron-LM: ❌ Commits have DIVERGED from a common ancestor
TARGET (main branch): https://github.com/yaoyu-33/Megatron-LM/commits/b73ae5cdab9d409fcface2b2f3c375710abe6911/
CURRENT (PR #1787 from update-megatron-lm-5247a1f): https://github.com/yaoyu-33/Megatron-LM/commits/5247a1f4600c258c8f5d40c3bd934f210dbf3698/

Please ensure all submodule commits are fast-forwards of the main branch before merging.

[github-actions]

❌ Submodule Fast-Forward Check Failed

Check based on commit: 6d03b70 (PR #1787 from update-megatron-lm-5247a1f)

✅ Submodules that are properly updated:

Megatron-Bridge: ✅ PR branch is ahead of main branch (fast-forward)

❌ Submodules that need attention:

Megatron-LM: ❌ Commits have DIVERGED from a common ancestor
TARGET (main branch): https://github.com/yaoyu-33/Megatron-LM/commits/b73ae5cdab9d409fcface2b2f3c375710abe6911/
CURRENT (PR #1787 from update-megatron-lm-5247a1f): https://github.com/yaoyu-33/Megatron-LM/commits/11dcbaca317133cc5c77c8bc4f54ed71d3b5d656/

Please ensure all submodule commits are fast-forwards of the main branch before merging.

[github-actions]

❌ Submodule Fast-Forward Check Failed

Check based on commit: 82d1059 (PR #1787 from update-megatron-lm-5247a1f)

✅ Submodules that are properly updated:

Megatron-Bridge: ✅ PR branch is ahead of main branch (fast-forward)

❌ Submodules that need attention:

Megatron-LM: ❌ Commits have DIVERGED from a common ancestor
TARGET (main branch): https://github.com/yaoyu-33/Megatron-LM/commits/b73ae5cdab9d409fcface2b2f3c375710abe6911/
CURRENT (PR #1787 from update-megatron-lm-5247a1f): https://github.com/yaoyu-33/Megatron-LM/commits/11dcbaca317133cc5c77c8bc4f54ed71d3b5d656/

Please ensure all submodule commits are fast-forwards of the main branch before merging.

[github-actions]

❌ Submodule Fast-Forward Check Failed

Check based on commit: fde1997 (PR #1787 from update-megatron-lm-5247a1f)

✅ Submodules that are properly updated:

Megatron-Bridge: ✅ PR branch is ahead of main branch (fast-forward)

❌ Submodules that need attention:

Megatron-LM: ❌ Commits have DIVERGED from a common ancestor
TARGET (main branch): https://github.com/yaoyu-33/Megatron-LM/commits/b73ae5cdab9d409fcface2b2f3c375710abe6911/
CURRENT (PR #1787 from update-megatron-lm-5247a1f): https://github.com/yaoyu-33/Megatron-LM/commits/11dcbaca317133cc5c77c8bc4f54ed71d3b5d656/

Please ensure all submodule commits are fast-forwards of the main branch before merging.