Python: Fix onnx pkg by pinning. Pin openai < 2.0. (#13284)

### Motivation and Context

For the latest onnxruntime 1.23.2 pkg: our GitHub Actions run is failing
because uv is not matching the macOS wheel tag.
Pinning to last-known-good until it's sorted out.

- Pin openai pkg < 2.0 until we can investigate if 2.0 brings in other
breaking changes.

### Contribution Checklist

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- [ ] The code builds clean without any errors or warnings
- [ ] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
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script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [ ] All unit tests pass, and I have added new tests where possible
- [ ] I didn't break anyone :smile: