Update maven.yml

Author: Maploop

.github/workflows/maven.yml

@@ -16,10 +16,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v3
-    - name: Set up JDK 11
+    - name: Set up JDK 21
       uses: actions/setup-java@v3
       with:
-        java-version: '11'
+        java-version: '21'
         distribution: 'temurin'
         cache: maven
     - name: Build with Maven