CohereEmbeddings: Add max_retries and request_timeout (#12275)

Add max_retries and request_timeout to CohereEmbeddings, akin to how it
works in OpenAIEmbeddings.

Since the Cohere client already implements these parameters, we can
simply pass them down.

Uses parameters from these two cohere client objects:

https://github.com/cohere-ai/cohere-python/blob/main/cohere/client.py

https://github.com/cohere-ai/cohere-python/blob/main/cohere/client_async.py

libs/langchain/langchain/embeddings/cohere.py

@@ -33,6 +33,11 @@ class CohereEmbeddings(BaseModel, Embeddings):
 
     cohere_api_key: Optional[str] = None
 
+    max_retries: Optional[int] = None
+    """Maximum number of retries to make when generating."""
+    request_timeout: Optional[float] = None
+    """Timeout in seconds for the Cohere API request."""
+
     class Config:
         """Configuration for this pydantic object."""
 
@@ -44,11 +49,18 @@ class CohereEmbeddings(BaseModel, Embeddings):
         cohere_api_key = get_from_dict_or_env(
             values, "cohere_api_key", "COHERE_API_KEY"
         )
+        max_retries = values.get("max_retries")
+        request_timeout = values.get("request_timeout")
+
         try:
             import cohere
 
-            values["client"] = cohere.Client(cohere_api_key)
-            values["async_client"] = cohere.AsyncClient(cohere_api_key)
+            values["client"] = cohere.Client(
+                cohere_api_key, max_retries=max_retries, timeout=request_timeout
+            )
+            values["async_client"] = cohere.AsyncClient(
+                cohere_api_key, max_retries=max_retries, timeout=request_timeout
+            )
         except ImportError:
             raise ValueError(
                 "Could not import cohere python package. "