Add chat_template_kwargs to ChatHuggingFace for passing extra options to apply_chat_template

### Checked other resources - [x] This is a feature request, not a bug report or usage question. - [x] I added a clear and descriptive title that summarizes the feature request. - [x] I used the GitHub search to find a similar feature request and didn't find it. - [x] I checked the LangChain documentation and API reference to see if this feature already exists. - [x] This is not related to the langchain-community package. ### Package (Required) - [ ] langchain - [ ] langchain-openai - [ ] langchain-anthropic - [ ] langchain-classic - [ ] langchain-core - [ ] langchain-model-profiles - [ ] langchain-tests - [ ] langchain-text-splitters - [ ] langchain-chroma - [ ] langchain-deepseek - [ ] langchain-exa - [ ] langchain-fireworks - [ ] langchain-groq - [x] langchain-huggingface - [ ] langchain-mistralai - [ ] langchain-nomic - [ ] langchain-ollama - [ ] langchain-openrouter - [ ] langchain-perplexity - [ ] langchain-qdrant - [ ] langchain-xai - [ ] Other / not sure / general ### Feature Description ChatHuggingFace._to_chat_prompt calls tokenizer.apply_chat_template with only hardcoded arguments (tokenize=False, add_generation_prompt=True). There is currently no way to pass additional keyword arguments to apply_chat_template without subclassing. Many recent models (QwQ, DeepSeek-R1, Qwen3, etc.) support enable_thinking in their chat templates, and other models may accept custom template kwargs. Users need a way to pass these options through ChatHuggingFace. Use Case: ### Use Case When using reasoning models like QwQ or DeepSeek-R1 via HuggingFacePipeline, I need to pass enable_thinking=True to the tokenizer's apply_chat_template. Currently the only workaround is subclassing ChatHuggingFace and overriding the private _to_chat_prompt method, which is fragile. chat = ChatHuggingFace( llm=pipeline, chat_template_kwargs={"enable_thinking": True}, ) ### Proposed Solution Add a chat_template_kwargs: dict[str, Any] field (default {}) to ChatHuggingFace, a…