change specified api-version

[olaoluwasalami]

@qingyun-wu @sonichi

Why are these changes needed?

gpt-4o has newer Azure OpenAI API version. I suggest simply changing API version in the sample config to:

"api_version": ""

Related issue number

Closes #2948

Checks

• [ ] I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://microsoft.github.io/autogen/docs/Contribute#documentation to build and test documentation locally.
• [ ] I've added tests (if relevant) corresponding to the changes introduced in this PR.
• [x] I've made sure all auto checks have passed.

[gitguardian[bot]]

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| GitGuardian id | GitGuardian status | Secret | Commit | Filename | | | -------------- | ------------------ | ------------------------------ | ---------------- | --------------- | -------------------- | | [10404662](https://dashboard.gitguardian.com/workspace/221093/incidents/10404662) | Triggered | Generic CLI Secret | d83e1dfcd137d6fc8a251ce67fb1ac72e3725181 | .github/workflows/dotnet-build.yml | [View secret](https://github.com/microsoft/autogen/commit/d83e1dfcd137d6fc8a251ce67fb1ac72e3725181#diff-ad500d44fcdc80118f5126903c29ba356c669ce8c155498faed0eb9272137d53L175) |

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1. Understand the implications of revoking this secret by investigating where it is used in your code. 2. Replace and store your secret safely. [Learn here](https://blog.gitguardian.com/secrets-api-management?utm_source=product&utm_medium=GitHub_checks&utm_campaign=check_run_comment) the best practices. 3. Revoke and [rotate this secret](https://docs.gitguardian.com/secrets-detection/secrets-detection-engine/detectors/generics/generic_cli_option_secret#revoke-the-secret?utm_source=product&utm_medium=GitHub_checks&utm_campaign=check_run_comment). 4. If possible, [rewrite git history](https://blog.gitguardian.com/rewriting-git-history-cheatsheet?utm_source=product&utm_medium=GitHub_checks&utm_campaign=check_run_comment). Rewriting git history is not a trivial act. You might completely break other contributing developers' workflow and you risk accidentally deleting legitimate data. To avoid such incidents in the future consider - following these [best practices](https://blog.gitguardian.com/secrets-api-management/?utm_source=product&utm_medium=GitHub_checks&utm_campaign=check_run_comment) for managing and storing secrets including API keys and other credentials - install [secret detection on pre-commit](https://docs.gitguardian.com/ggshield-docs/integrations/git-hooks/pre-commit?utm_source=product&utm_medium=GitHub_checks&utm_campaign=check_run_comment) to catch secret before it leaves your machine and ease remediation.

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