community[patch]: Fixed the 'aembed' method of 'CohereEmbeddings'. (#16497)

**Description:**
- The existing code was trying to find a `.embeddings` property on the
`Coroutine` returned by calling `cohere.async_client.embed`.
- Instead, the `.embeddings` property is present on the value returned
by the `Coroutine`.
- Also, it seems that the original cohere client expects a value of
`max_retries` to not be `None`. Hence, setting the default value of
`max_retries` to `3`.

---------

Co-authored-by: Bagatur <baskaryan@gmail.com>

libs/community/langchain_community/embeddings/cohere.py

@@ -34,7 +34,7 @@ class CohereEmbeddings(BaseModel, Embeddings):
 
     cohere_api_key: Optional[str] = None
 
-    max_retries: Optional[int] = None
+    max_retries: Optional[int] = 3
     """Maximum number of retries to make when generating."""
     request_timeout: Optional[float] = None
     """Timeout in seconds for the Cohere API request."""
@@ -92,11 +92,13 @@ class CohereEmbeddings(BaseModel, Embeddings):
     async def aembed(
         self, texts: List[str], *, input_type: Optional[str] = None
     ) -> List[List[float]]:
-        embeddings = await self.async_client.embed(
-            model=self.model,
-            texts=texts,
-            input_type=input_type,
-            truncate=self.truncate,
+        embeddings = (
+            await self.async_client.embed(
+                model=self.model,
+                texts=texts,
+                input_type=input_type,
+                truncate=self.truncate,
+            )
         ).embeddings
         return [list(map(float, e)) for e in embeddings]