git: openjdk/jdk-sandbox: json: Remove Thread Safety header. Combine with mutability sentence

[duke]

Changeset: 117bd01d
Branch: json
Author:    Justin Lu <justin.lu at oracle.com>
Date:      2025-05-12 10:50:57 +0000
URL:       https://git.openjdk.org/jdk-sandbox/commit/117bd01d88e5ec63cc359eec737413d2625b810a

Remove Thread Safety header. Combine with mutability sentence

! src/java.base/share/classes/java/util/json/JsonValue.java