git: openjdk/jdk-sandbox: json: Restore copyright year of PreviewFeature.java

[duke]

Changeset: 29d0fa7b
Branch: json
Author:    Naoto Sato <naoto.sato at oracle.com>
Date:      2025-10-01 10:37:20 +0000
URL:       https://git.openjdk.org/jdk-sandbox/commit/29d0fa7bc5dba0a798a94b5b83294937316b9c3f

Restore copyright year of PreviewFeature.java

! src/java.base/share/classes/jdk/internal/javac/PreviewFeature.java