community:Fix a bug of LLM in moonshot (#25878)

- **Description:** When useing LLM integration moonshot,it's occurring
error "'Moonshot' object has no attribute '_client'",it's because of the
"_client" that is private in pydantic v1.0 so that we can't use it.I
turn "_client" into "client" , the error to be resolved!
- **Issue:** the issue #24390 
- **Dependencies:** none
- **Twitter handle:** @Rainsubtime




- [x] **Lint and test**: Run `make format`, `make lint` and `make test`
from the root of the package(s) you've modified. See contribution
guidelines for more: https://python.langchain.com/docs/contributing/

Co-authored-by: Cyue <Cyue_work2001@163.com>

libs/community/langchain_community/llms/moonshot.py

@@ -33,7 +33,7 @@ class _MoonshotClient(BaseModel):
 class MoonshotCommon(BaseModel):
     """Common parameters for Moonshot LLMs."""
 
-    _client: _MoonshotClient
+    client: _MoonshotClient
     base_url: str = MOONSHOT_SERVICE_URL_BASE
     moonshot_api_key: Optional[SecretStr] = Field(default=None, alias="api_key")
     """Moonshot API key. Get it here: https://platform.moonshot.cn/console/api-keys"""
@@ -84,7 +84,7 @@ class MoonshotCommon(BaseModel):
             get_from_dict_or_env(values, "moonshot_api_key", "MOONSHOT_API_KEY")
         )
 
-        values["_client"] = _MoonshotClient(
+        values["client"] = _MoonshotClient(
             api_key=values["moonshot_api_key"],
             base_url=values["base_url"]
             if "base_url" in values
@@ -125,7 +125,7 @@ class Moonshot(MoonshotCommon, LLM):
         request = self._invocation_params
         request["messages"] = [{"role": "user", "content": prompt}]
         request.update(kwargs)
-        text = self._client.completion(request)
+        text = self.client.completion(request)
         if stop is not None:
             # This is required since the stop tokens
             # are not enforced by the model parameters