Add Qwen3-VL support with Megatron-FSDP

[xuwchen]

What does this PR do ?

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flowchart LR
    A[Pre-checks] --> B[PR Tests]
    subgraph Code Review/Approval
        C1[Expert Review] --> C2[Final Review]
    end
    B --> C1
    C2 --> D[Merge]

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[shjwudp]

Could you explain the purpose of adding this function? As I understand it, group.requires_grad is derived from param.requires_grad.

[Phlip79]

@xuwchen please add a description to the PR.

[xuwchen]

/ok to test 7d99185

[ko3n1g]

🔄 Merge queue validation started!

You can track the progress here: https://github.com/NVIDIA/Megatron-LM/actions/runs/21939946112