Qt AI Assistant version 0.9.9 (#48)

## Describe your changes

Bump Qt AI Assistant to version 0.9.9

## Checklist

- [x] I have run `npm run all` to validate my changes
- [x] I have made sure my commits are [signed]
- [x] I have read and I agree with the [Qt Creator Extensions Store
Publisher
Terms](https://github.com/qt-creator/extension-registry/blob/main/documentation/publisher-terms.pdf)

Author: DanSoQt