fix: resolve header.uid' length must be less or equal than 32 on Spark V1.5

[Kennytian]

Description

fix: parameter user exceeded max length(32 words) when invoking Spark V1.5 llm

Fixes #2982

I referenced this modify：
https://github.com/langgenius/dify/blob/main/api/core/model_runtime/model_providers/moonshot/llm/llm.py#L16

Type of Change

Please delete any options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Manual test

Suggested Checklist:

• I have performed a self-review of my own code
• I have commented on my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods
• optional I have made corresponding changes to the documentation
• optional I have added tests that prove my fix is effective or that my feature works
• optional New and existing unit tests pass locally with my changes

[crazywoola]

I checked the official site of Spark. It's not deprecated.

[Kennytian]

I checked the official site of Spark. It's not deprecated.

Thanks for your response, I have revised my submission, referencing the same issue with the moonshot LLM.

@crazywoola Please review it again, thank you!