Update JDK version from 17 to 21 in workflow

Author: PonderFox0643

.github/workflows/maven-publish.yml

@@ -16,10 +16,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v3
-    - name: Set up JDK 17
+    - name: Set up JDK 21
       uses: actions/setup-java@v3
       with:
-        java-version: '17'
+        java-version: '21'
         distribution: 'temurin'
         server-id: github # Value of the distributionManagement/repository/id field of the pom.xml
         settings-path: ${{ github.workspace }} # location for the settings.xml file