Update gradle.yml

Author: GsTio86

.github/workflows/gradle.yml

@@ -36,7 +36,7 @@ jobs:
         echo "VERSION=$VERSION" >> $GITHUB_ENV
 
     - name: Archive build artifacts
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: PixelmonSync
         path: build/libs/*.jar