git: openjdk/jdk-sandbox: json: Implement JEP 502 Stable Values instead of internal annotation

[duke]

Changeset: c852666f
Branch: json
Author:    Justin Lu <justin.lu at oracle.com>
Date:      2025-04-30 15:32:50 +0000
URL:       https://git.openjdk.org/jdk-sandbox/commit/c852666f737d068a13fdfb74bc3864aea39796dd

Implement JEP 502 Stable Values instead of internal annotation

! src/java.base/share/classes/java/util/json/JsonNumberImpl.java
! src/java.base/share/classes/java/util/json/JsonStringImpl.java