Fix broken link to Java Client API Reference in doc

The link to the Java Client API Reference (https://min.io/docs/minio/linux/developers/java/API.html) is currently returning a 404 page.
It looks like the page may have moved or the URL might be outdated.

This PR updates the link to the correct location.

<img width="2302" height="1171" alt="Image" src="https://github.com/user-attachments/assets/be141989-086d-42b7-91c8-26af530ba9fe" />