Bump express from 5.1.0 to 5.2.1 in /sandbox

Bumps [express](https://github.com/expressjs/express) from 5.1.0 to 5.2.1.
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/master/History.md)
- [Commits](expressjs/express@v5.1.0...v5.2.1)

---
updated-dependencies:
- dependency-name: express
  dependency-version: 5.2.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

sandbox/package-lock.json

@@ -9,7 +9,7 @@
   "license": "Unlicense",
   "private": true,
   "dependencies": {
-    "express": "^5.0.0-alpha.8",
+    "express": "^5.2.1",
     "loglevel": "^1.7.1",
     "uuid": "^8.3.2",
     "yargs-unparser": "^2.0.0"