fix: change version of upload-artifact

Author: ThomasChourret

.github/workflows/build.yml

@@ -24,7 +24,7 @@ jobs:
         run: mvn clean package
 
       - name: 📦 Upload plugin jar
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: proxy-plugin-jar
           path: target/*.jar