deps: bump actions/upload-artifact to v6

Upgrade upload-artifact in release workflow to v6.

Author: dependabot[bot]

.github/workflows/release.yml

@@ -40,7 +40,7 @@ jobs:
           ./create-release-zips.sh
 
       - name: Upload artifacts
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: extension-zips
           path: dist/*.zip