update download-artifact in Github Actions to v4

Author: Calvinn Ng

.github/workflows/main.yaml

@@ -170,7 +170,7 @@ jobs:
         run: git pull origin main
 
       # 1. Download the artifacts
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
 
       # 2. Publish the extension to VS Code Marketplace
       - name: Publish to VS Code Marketplace