chore: Update release workflow to new assets directory

.github/workflows/release.yml

@@ -41,4 +41,4 @@ jobs:
           tag="${{ github.ref_name }}"
           body="Release $tag"
           gh release create --draft "$tag" --title "$tag" --notes "$body" --generate-notes --prerelease
-          gh release upload "${{ github.ref_name }}" assets/powersync_db.worker.js
+          gh release upload "${{ github.ref_name }}" packages/powersync/assets/powersync_db.worker.js