chore: Together async client (#1510)

# What does this PR do?
Uses together async client instead of sync client

[//]: # (If resolving an issue, uncomment and update the line below)

## Test Plan
Command to run the test is in the image below(2 tests fail, and they
were failing for the old stable version as well with the same errors.)
<img width="1689" alt="image"
src="https://github.com/user-attachments/assets/503db720-5379-425d-9844-0225010e41a1"
/>


[//]: # (## Documentation)

---------

Co-authored-by: sarthakdeshpande <sarthak.deshpande@engati.com>

llama_stack/providers/remote/inference/together/together.py

@@ -6,7 +6,7 @@
 
 from typing import AsyncGenerator, List, Optional, Union
 
-from together import Together
+from together import AsyncTogether
 
 from llama_stack.apis.common.content_types import (
     InterleavedContent,
@@ -59,12 +59,15 @@ class TogetherInferenceAdapter(ModelRegistryHelper, Inference, NeedsRequestProvi
     def __init__(self, config: TogetherImplConfig) -> None:
         ModelRegistryHelper.__init__(self, MODEL_ENTRIES)
         self.config = config
+        self._client = None
 
     async def initialize(self) -> None:
         pass
 
     async def shutdown(self) -> None:
-        pass
+        if self._client:
+            await self._client.close()
+            self._client = None
 
     async def completion(
         self,
@@ -91,35 +94,32 @@ class TogetherInferenceAdapter(ModelRegistryHelper, Inference, NeedsRequestProvi
         else:
             return await self._nonstream_completion(request)
 
-    def _get_client(self) -> Together:
-        together_api_key = None
-        config_api_key = self.config.api_key.get_secret_value() if self.config.api_key else None
-        if config_api_key:
-            together_api_key = config_api_key
-        else:
-            provider_data = self.get_request_provider_data()
-            if provider_data is None or not provider_data.together_api_key:
-                raise ValueError(
-                    'Pass Together API Key in the header X-LlamaStack-Provider-Data as { "together_api_key": <your api key>}'
-                )
-            together_api_key = provider_data.together_api_key
-        return Together(api_key=together_api_key)
+    def _get_client(self) -> AsyncTogether:
+        if not self._client:
+            together_api_key = None
+            config_api_key = self.config.api_key.get_secret_value() if self.config.api_key else None
+            if config_api_key:
+                together_api_key = config_api_key
+            else:
+                provider_data = self.get_request_provider_data()
+                if provider_data is None or not provider_data.together_api_key:
+                    raise ValueError(
+                        'Pass Together API Key in the header X-LlamaStack-Provider-Data as { "together_api_key": <your api key>}'
+                    )
+                together_api_key = provider_data.together_api_key
+            self._client = AsyncTogether(api_key=together_api_key)
+        return self._client
 
     async def _nonstream_completion(self, request: CompletionRequest) -> ChatCompletionResponse:
         params = await self._get_params(request)
-        r = self._get_client().completions.create(**params)
+        client = self._get_client()
+        r = await client.completions.create(**params)
         return process_completion_response(r)
 
     async def _stream_completion(self, request: CompletionRequest) -> AsyncGenerator:
         params = await self._get_params(request)
-
-        # if we shift to TogetherAsyncClient, we won't need this wrapper
-        async def _to_async_generator():
-            s = self._get_client().completions.create(**params)
-            for chunk in s:
-                yield chunk
-
-        stream = _to_async_generator()
+        client = await self._get_client()
+        stream = await client.completions.create(**params)
         async for chunk in process_completion_stream_response(stream):
             yield chunk
 
@@ -184,25 +184,21 @@ class TogetherInferenceAdapter(ModelRegistryHelper, Inference, NeedsRequestProvi
 
     async def _nonstream_chat_completion(self, request: ChatCompletionRequest) -> ChatCompletionResponse:
         params = await self._get_params(request)
+        client = self._get_client()
         if "messages" in params:
-            r = self._get_client().chat.completions.create(**params)
+            r = await client.chat.completions.create(**params)
         else:
-            r = self._get_client().completions.create(**params)
+            r = await client.completions.create(**params)
         return process_chat_completion_response(r, request)
 
     async def _stream_chat_completion(self, request: ChatCompletionRequest) -> AsyncGenerator:
         params = await self._get_params(request)
+        client = self._get_client()
+        if "messages" in params:
+            stream = await client.chat.completions.create(**params)
+        else:
+            stream = await client.completions.create(**params)
 
-        # if we shift to TogetherAsyncClient, we won't need this wrapper
-        async def _to_async_generator():
-            if "messages" in params:
-                s = self._get_client().chat.completions.create(**params)
-            else:
-                s = self._get_client().completions.create(**params)
-            for chunk in s:
-                yield chunk
-
-        stream = _to_async_generator()
         async for chunk in process_chat_completion_stream_response(stream, request):
             yield chunk
 
@@ -240,7 +236,8 @@ class TogetherInferenceAdapter(ModelRegistryHelper, Inference, NeedsRequestProvi
         assert all(not content_has_media(content) for content in contents), (
             "Together does not support media for embeddings"
         )
-        r = self._get_client().embeddings.create(
+        client = self._get_client()
+        r = await client.embeddings.create(
             model=model.provider_resource_id,
             input=[interleaved_content_as_str(content) for content in contents],
         )