update some github actions versions

Author: dvojtise

.github/workflows/maven-publish.yml

@@ -16,7 +16,7 @@ jobs:
       packages: write
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Set up JDK 11
       uses: actions/setup-java@v2
       with:

.github/workflows/maven.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Set up JDK 11
       uses: actions/setup-java@v2
       with:
@@ -36,7 +36,7 @@ jobs:
     - name: Stage result files
       run: mkdir staging && cp sync-git-submodules-branches/target/*.jar staging
     - name: Upload Artifacts
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v4
       with:
         name: Package
         path: staging