ci: build the Java binding on JDK 25 LTS (22 is EOL) (#292)

Java 22 is a non-LTS that has reached end of life; bump the build JDK in
ci.yml and release.yml to the 25 LTS. The pom pins `maven.compiler.release`
to 22, so the emitted bytecode and the Java 22+ runtime floor (FFM API, final
since 22) are unchanged. Not 21 — FFM was only preview there.

.github/workflows/release.yml

@@ -757,11 +757,11 @@ jobs:
 
       # setup-java writes a settings.xml with the 'central' server credentials
       # (mapped from the env vars below) and imports the GPG signing key.
-      - name: Set up JDK 22 + Maven Central credentials + GPG
+      - name: Set up JDK 25 + Maven Central credentials + GPG
         uses: actions/setup-java@be666c2fcd27ec809703dec50e508c2fdc7f6654 # v5.2.0
         with:
           distribution: temurin
-          java-version: "22"
+          java-version: "25"
           server-id: central
           server-username: CENTRAL_USERNAME
           server-password: CENTRAL_PASSWORD