chore(ci): update GitHub Actions to latest versions (#18)

Author: marevol

.github/workflows/maven.yml

@@ -19,9 +19,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Set up JDK 21
-      uses: actions/setup-java@v2
+      uses: actions/setup-java@v4
       with:
         java-version: '21'
         distribution: 'temurin'