no qwen3_6_nothink template

### Reminder - [x] I have read the above rules and searched the existing issues. ### System Info When we fine-tuned Qwen3.6 with LoRA, we encountered the following error: [rank3]: File "/app/src/llamafactory/data/template.py", line 639, in get_template_and_fix_tokenizer [rank3]: raise ValueError(f"Template {data_args.template} does not exist.")** ### Reproduction ```text Put your message here. ``` ### Others _No response_