change jdk version and add maven in action

.gitea/workflows/maven.yaml

@@ -10,10 +10,14 @@ jobs:
     steps:
       - name: Checkout the repo
         uses: actions/checkout@v4
-          - name: Setup JDK 21
+      - name: Set up Maven
+        uses: stCarolas/setup-maven@v5
+        with:
+          maven-version: '3.8.2'
+      - name: Set up JDK 23
         uses: actions/setup-java@v4
         with:
-               java-version: 21
+          java-version: 23
           distribution: 'temurin'
           cache: maven
       - name: Build with Maven