Update quickstart-python-openai.md: Python 3.8

AFAIS only Python 3.8 is necessary
https://github.com/Azure/azure-sdk-for-python/tree/main/sdk/ai/azure-ai-projects

Author: bmerkle

articles/ai-services/agents/includes/quickstart-python-openai.md

@@ -13,7 +13,7 @@ ms.date: 11/13/2024
 ## Prerequisites
 
 * An Azure subscription - [Create one for free](https://azure.microsoft.com/free/cognitive-services).
-* [Python 3.13 or later](https://www.python.org/)
+* [Python 3.8 or later](https://www.python.org/)
 * Make sure you have the **Azure AI Developer** [RBAC role](../../../ai-studio/concepts/rbac-ai-studio.md) assigned at the appropriate level.
 * Install [the Azure CLI and the machine learning extension](/azure/machine-learning/how-to-configure-cli). If you have the CLI already installed, make sure it's updated to the latest version.
 
@@ -96,4 +96,4 @@ with AIProjectClient.from_connection_string(
 
         messages = client.beta.threads.messages.list(thread_id=thread.id)
         print(f"Messages: {messages}")
-```
+```