Bump actions/checkout from 3 to 4 (#22)

Author: zefir-git

.github/workflows/maven.yaml

@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up JDK 17
         uses: actions/setup-java@v4
         with: