Use Java 21 for GraalVM native test

Author: acogoluegnes

.github/workflows/test-native-image.yml

@@ -25,7 +25,7 @@ jobs:
         uses: graalvm/setup-graalvm@v1
         with:
           version: 'latest'
-          java-version: '17'
+          java-version: '21'
           components: 'native-image'
           cache: 'maven'
       - name: Start broker