AOAI: add temporary Assistants v2 Python note

Author: trrwilson

articles/ai-services/openai/includes/assistants-python.md

@@ -30,9 +30,12 @@ ms.date: 02/01/2024
 Install the OpenAI Python client library with:
 
 ```console
-pip install openai
+pip install openai==v1.20.0
 ```
 
+> [!NOTE]
+> Azure OpenAI does not yet support Assistants V2. Please use the v1.20.0 release of the OpenAI Python library until V2 support is available.
+
 > [!NOTE]
 > This library is maintained by OpenAI. Refer to the [release history](https://github.com/openai/openai-python/releases) to track the latest updates to the library.