[Model] Modify the gate implementation of glm4_moe

[jeejeelee]

Essential Elements of an Effective PR Description Checklist

• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
• (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.

Purpose

In the transformers implementation, the gate isn't an nn.Linear, so we cannot use ReplicatedLinear.
FIX #22751 (comment) (LoRA related issue)

Test Plan

Test Result

(Optional) Documentation Update

[github-actions]

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[gemini-code-assist]

Code Review

This pull request correctly modifies the gate implementation in the glm4_moe model. The change from ReplicatedLinear to a standard torch.nn.Linear layer is appropriate, as it aligns with the original Hugging Face Transformers implementation where the gate is not a standard parallelizable linear layer. This resolves the underlying issue, and the related adjustments to the forward pass and documentation are also correct. The changes are well-justified and improve the model's correctness and compatibility.