Python: Add release_candidate decorator (microsoft#11368)

### Motivation and Context

Add release_candidate decorator for AzureAssistantAgent.

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### Description

Add release_candidate decorator for AzureAssistantAgent.

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### Contribution Checklist

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- [X] The code builds clean without any errors or warnings
- [X] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
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raises no violations
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Author: moonbox3

python/semantic_kernel/agents/open_ai/azure_assistant_agent.py

@@ -11,9 +11,11 @@
 from semantic_kernel.connectors.ai.open_ai.settings.azure_open_ai_settings import AzureOpenAISettings
 from semantic_kernel.exceptions.agent_exceptions import AgentInitializationException
 from semantic_kernel.utils.authentication.entra_id_authentication import get_entra_auth_token
+from semantic_kernel.utils.feature_stage_decorator import release_candidate
 from semantic_kernel.utils.telemetry.user_agent import APP_INFO, prepend_semantic_kernel_to_user_agent
 
 
+@release_candidate
 class AzureAssistantAgent(OpenAIAssistantAgent):
     """An Azure Assistant Agent class that extends the OpenAI Assistant Agent class."""