Update test.yml

Author: gkwan-ibm

.github/workflows/test.yml

@@ -48,11 +48,11 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v3
         with:
           distribution: 'semeru'
-          java-version: 17
+          java-version: 21
       - run: unset _JAVA_OPTIONS
       - name: Run tests
         run: sudo -E ../scripts/testApp.sh