Fix CI (#439)

* Update maven.yml

* Fix typo

* Use Java 21

* Update maven.yml

Author: espidev

.github/workflows/maven.yml

@@ -15,16 +15,16 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
-    - name: Set up JDK 16
-      uses: actions/setup-java@v3
+    - uses: actions/checkout@v4
+    - name: Set up JDK
+      uses: actions/setup-java@v4
       with:
-        java-version: '16'
+        java-version: '21'
         distribution: 'temurin'
         cache: maven
     - name: Build with Maven
       run: mvn -B package --file pom.xml
-    - uses: actions/upload-artifact@v3
+    - uses: actions/upload-artifact@v4
       with:
         name: Artifacts
         path: target