Repository: langchain
Issue: Update default values of minimax_api_host and model in MiniMaxChat __init__
Labels: 🤖:bug

### Checked other resources

- [x] I added a very descriptive title to this issue.
- [x] I searched the LangChain documentation with the integrated search.
- [x] I used the GitHub search to find a similar question and didn't find it.
- [x] I am sure that this is a bug in LangChain rather than my code.
- [x] The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package).

### Example Code

The following code:

```python

from langchain_community.chat_models import MiniMaxChat

api_key = "YOUR_API_KEY"
chat = MiniMaxChat(api_key=api_key)
messages = [
    ("human", "Hello, how are you?"),
]

resp = chat.invoke(messages)
print(resp)
```

### Error Message and Stack Trace (if applicable)


```
Traceback (most recent call last):
  File "/home/work/langchain/bug_report.py", line 13, in <module>
    resp = chat.invoke(messages)
  File "/home/work/langchain/venv/lib/python3.10/site-packages/langchain_core/language_models/chat_models.py", line 286, in invoke
    self.generate_prompt(
  File "/home/work/langchain/venv/lib/python3.10/site-packages/langchain_core/language_models/chat_models.py", line 786, in generate_prompt
    return self.generate(prompt_messages, stop=stop, callbacks=callbacks, **kwargs)
  File "/home/work/langchain/venv/lib/python3.10/site-packages/langchain_core/language_models/chat_models.py", line 643, in generate
    raise e
  File "/home/work/langchain/venv/lib/python3.10/site-packages/langchain_core/language_models/chat_models.py", line 633, in generate
    self._generate_with_cache(
  File "/home/work/langchain/venv/lib/python3.10/site-packages/langchain_core/language_models/chat_models.py", line 851, in _generate_with_cache
    result = self._generate(
  File "/home/work/langchain/venv/lib/python3.10/site-packages/langchain_community/chat_models/minimax.py", line 515, in _generate
    return self._create_chat_result(response.json())
  File "/home/work/langchain/venv/lib/python3.10/site-packages/langchain_community/chat_models/minimax.py", line 429, in _create_chat_result
    for res in response["choices"]:
KeyError: 'choices'
```

### Description

* I am trying to run `MiniMaxChat`using default settings
* The underlying problem is that the default values for parameters do not work
    -  `minimax_api_host` is `https://api.minimax.chat/v1/text/chatcompletion_v2`, whereas it should be `https://api.minimaxi.chat/v1/text/chatcompletion_v2` (note the `i` -> `minimax` -> `minimaxi`)
    - `model` is `abab6.5-chat`, whereas it should be `abab6.5s-chat` (note the `s`)
    - Consequently, the received response is not a succesful one, so the `choices` key is not present in it
* Using overriden parameters `MiniMaxChat(api_key=api_key, model="abab6.5s-chat", minimax_api_host="https://api.minimaxi.chat/v1/text/chatcompletion_v2")` yields successful result
* Additionally there is a problem with the code itself at the point of the raised exception. It's difficult to comprehend for a user why the `KeyError` was raised - but that is for another issue probably.
    - In my opinion, it would be better to fail early with an informative error message - invalid API key, insufficient balance, invalid model name etc.

### System Info

`python -m langchain_core.sys_info` yields:

```
System Information
------------------
> OS:  Linux
> OS Version:  #52~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Mon Dec  9 15:00:52 UTC 2
> Python Version:  3.10.12 (main, Nov  6 2024, 20:22:13) [GCC 11.4.0]

Package Information
-------------------
> langchain_core: 0.3.30
> langchain: 0.3.14
> langchain_community: 0.3.14
> langsmith: 0.2.11
> langchain_minimax: Installed. No version info available.
> langchain_openai: 0.3.0
> langchain_text_splitters: 0.3.5

Optional packages not installed
-------------------------------
> langserve

Other Dependencies
------------------
> aiohttp: 3.11.11
> async-timeout: 4.0.3
> dataclasses-json: 0.6.7
> httpx: 0.28.1
> httpx-sse: 0.4.0
> jsonpatch: 1.33
> langsmith-pyo3: Installed. No version info available.
> numpy: 1.26.4
> openai: 1.59.8
> orjson: 3.10.14
> packaging: 24.2
> pydantic: 2.10.5
> pydantic-settings: 2.7.1
> PyYAML: 6.0.2
> requests: 2.32.3
> requests-toolbelt: 1.0.0
> SQLAlchemy: 2.0.37
> tenacity: 9.0.0
> tiktoken: 0.8.0
> typing-extensions: 4.12.2
> zstandard: Installed. No version info available.
```