Feat/support 302ai provider (#8742)

### What problem does this PR solve?

Support 302.AI provider.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

rag/llm/sequence2txt_model.py

@@ -208,7 +208,6 @@ class GiteeSeq2txt(Base):
         self.client = OpenAI(api_key=key, base_url=base_url)
         self.model_name = model_name
 
-
 class DeepInfraSeq2txt(Base):
     _FACTORY_NAME = "DeepInfra"