updated java version

Author: rahul15sel

.github/workflows/ci.yml

@@ -16,11 +16,11 @@ jobs:
         uses: actions/checkout@v4
 
       # 2. Setup Java
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
           distribution: "temurin"
-          java-version: "17"
+          java-version: "21"
 
       # 3. Cache Maven dependencies (speeds up builds)
       - name: Cache Maven packages