Merge pull request viperproject#529 from viperproject/meilers_update_…

…upload_artifact

Update upload artifact version

.github/workflows/ci.yml

@@ -30,7 +30,7 @@ jobs:
         echo "Silver: commit $(git -C silver rev-parse HEAD)" >> versions.txt
       # first line overwrites versions.txt in case it already exists, all other append to the file
     - name: Upload version file
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v4
       with:
         name: versions-${{ matrix.name }}.txt
         path: versions.txt
@@ -67,7 +67,7 @@ jobs:
       run: sbt "set test in assembly := {}" clean assembly
 
     - name: Upload Carbon fat JAR
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v4
       with:
         name: carbon-jar
         path: target/scala-2.13/carbon.jar