Bump upload-artifact and download-artifact to v4

References #685.

.github/workflows/ci-main.yml

@@ -77,11 +77,11 @@ jobs:
           ./src/test/resources/run-s3-tests.sh
 
       #Store the target
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v4
         with:
           name: s3proxy
           path: target/s3proxy
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v4
         with:
           name: pom
           path: pom.xml
@@ -91,11 +91,11 @@ jobs:
     needs: [runTests, meta]
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/download-artifact@v2
+      - uses: actions/download-artifact@v4
         with:
           name: s3proxy
           path: target
-      - uses: actions/download-artifact@v2
+      - uses: actions/download-artifact@v4
         with:
           name: pom
           path: .