docs: HuggingFace pipeline returns the prompt if return_full_text is not set (#25916)

Thank you for contributing to LangChain!

**Description:**
The current documentation of using the Huggingface with Langchain needs
to set return_full_text as False otherwise pipeline by default returns
both the prompt and response as output.


Code to reproduce:
```python
from langchain_huggingface import ChatHuggingFace, HuggingFacePipeline
from langchain_core.messages import (
    HumanMessage,
    SystemMessage,
)

llm = HuggingFacePipeline.from_model_id(
    model_id="microsoft/Phi-3.5-mini-instruct",
    task="text-generation",
    pipeline_kwargs=dict(
        max_new_tokens=512,
        do_sample=False,
        repetition_penalty=1.03,
        # return_full_text=False
    ),
    device=0
)

chat_model = ChatHuggingFace(llm=llm)

messages = [
    SystemMessage(content="You're a helpful assistant"),
    HumanMessage(
        content="What happens when an unstoppable force meets an immovable object?"
    ),
]

ai_msg = chat_model.invoke(messages)
print(ai_msg.content)
```
Output:
```
<|system|>
You're a helpful assistant<|end|>
<|user|>
What happens when an unstoppable force meets an immovable object?<|end|>
<|assistant|>
 The scenario of an "unstoppable force" meeting an "immovable object" is a classic paradox that has puzzled philosophers, scientists, and thinkers for centuries. In physics, however, there are no such things as truly unstoppable forces or immovable objects because all physical entities have mass and interact with other masses through fundamental forces (like gravity).

When we consider the laws of motion, particularly Newton's third law which states that for every action, there is an equal and opposite reaction, it becomes clear that if one were to exist, the other would necessarily be negated by the interaction. For example, if you push against a solid wall with great force, the wall exerts an equal and opposite force back on you, preventing your movement.

In theoretical discussions, this paradox often serves as a thought experiment to explore concepts like determinism versus free will, the limits of physical laws, and the nature of reality itself. However, in practical terms, any force applied to an object will result in some form of deformation, transfer of energy, or movement, depending on the properties of both the force and the object.

So while the idea of an unstoppable force and an immovable object remains a fascinating philosophical conundrum, it does not hold up under the scrutiny of physical laws as we understand them.
```

---------

Co-authored-by: Kirushikesh D B kirushi@ibm.com <kirushi@cccxl012.pok.ibm.com>

docs/docs/integrations/chat/huggingface.ipynb

@@ -404,6 +404,7 @@
     "        max_new_tokens=512,\n",
     "        do_sample=False,\n",
     "        repetition_penalty=1.03,\n",
+    "        return_full_text=False,\n",
     "    ),\n",
     "    model_kwargs={\"quantization_config\": quantization_config},\n",
     ")\n",