Fix typo in LocalAgent
Author: jamartin9
Pull request: yes

# What does this PR do?

This PR fixes a typo in LocalAgent. 

Crash Log:
```
Traceback (most recent call last):
  File "/gnu/git/hf-agent/./agent.py", line 18, in <module>
    agent.run(prompt)
  File "/gnu/git/hf-agent/venv/lib/python3.11/site-packages/transformers/tools/agents.py", line 335, in run
    result = self.generate_one(prompt, stop=["Task:"])
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/gnu/git/hf-agent/venv/lib/python3.11/site-packages/transformers/tools/agents.py", line 731, in generate_one
    encoded_inputs = self.tokenizer(prompt, return_tensors="pt").to(self._model_device)
                                                                    ^^^^^^^^^^^^^^^^^^
  File "/gnu/git/hf-agent/venv/lib/python3.11/site-packages/transformers/tools/agents.py", line 727, in _model_device
    for param in self.mode.parameters():
                 ^^^^^^^^^
AttributeError: 'LocalAgent' object has no attribute 'mode'. Did you mean: 'model'?
```

Code that triggered the above crash
```
#!/usr/bin/env python3

import torch
from transformers import LocalAgent

model = "bigcode/tiny_starcoder_py"

agent = LocalAgent.from_pretrained(model, torch_dtype=torch.bfloat16)

text = "Sally sold sea shells down by the seashore."

prompt = "Summarize the text given in the variable `text` and read it out loud."

agent.run(prompt, text=text)
```


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Comments:
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