Bump GitHub Actions versions

Author: FDelporte

.github/workflows/maven.yml

@@ -11,15 +11,14 @@ on:
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
 
     steps:
     - uses: actions/checkout@v4
-    - name: Set up JDK 17
+    - name: Set up JDK 21
       uses: actions/setup-java@v1
       with:
-        java-version: 17
+        java-version: 21
     - name: Build with Maven
       run: mvn -B package --file pom.xml -DskipTests
     - name: Make staging directory