Python: Upgrade AOAI api version to latest GA: 2024-10-21 (#10118)

### Motivation and Context

The current DEFAULT_AZURE_API_VERSION is stale at 2024-06-01. The
[latest GA API
VERSION](https://learn.microsoft.com/en-us/azure/ai-services/openai/api-version-deprecation#latest-ga-api-release)
is 2024-10-21.

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### Description

This PR upgrades the DEFAULT_AZURE_API_VERSION to be the latest GA
2024-10-21. This default version is used if an api_version is not
supplied to the AzureChatCompletion constructor.
- Closes #10117

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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)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [X] All unit tests pass, and I have added new tests where possible
- [X] I didn't break anyone 😄

python/semantic_kernel/connectors/ai/open_ai/const.py

@@ -2,4 +2,4 @@
 
 from typing import Final
 
-DEFAULT_AZURE_API_VERSION: Final[str] = "2024-06-01"
+DEFAULT_AZURE_API_VERSION: Final[str] = "2024-10-21"