Update cudf-java deploy workflow to set stable version in projects-to-versions.json

[AyodeAwe]

Summary

• The deploy-cudf-java-docs workflow uploads javadocs to S3 and enables the stable link in _data/docs.yml, but doesn't update ci/customization/projects-to-versions.json with the stable version number
• This means download_from_s3.sh won't pull the stable cudf-java docs during the main site deploy
• This PR adds a jq step to also set "stable": "<version>" for cudf-java in projects-to-versions.json

[netlify]

✅ Deploy Preview for docs-rapids-ai ready!

Built without sensitive environment variables

Name	Link
🔨 Latest commit	16360ff
🔍 Latest deploy log	https://app.netlify.com/projects/docs-rapids-ai/deploys/69a069fe4805700008702a7e
😎 Deploy Preview	https://deploy-preview-752--docs-rapids-ai.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.