Add JDK25 as a Target

### Feature Request / Improvement

JDK25 has been available for almost a year and new versions of Spark now support JDK25. I have a need for JDK25 in a package that consumes Iceberg.

https://openjdk.org/projects/jdk/25/ for more information.

### Query engine

_No response_

### Willingness to contribute

- [x] I can contribute this improvement/feature independently
- [ ] I would be willing to contribute this improvement/feature with guidance from the Iceberg community
- [ ] I cannot contribute this improvement/feature at this time

Start by locating the existing JDK target configuration and comparing how currently supported Java versions are declared. Add JDK25 wherever the target versions are defined, then run the relevant build and compatibility checks to confirm the project supports it.

Written by the indexing model from the issue text.