Bump qs and express in /backend

Bumps [qs](https://github.com/ljharb/qs) to 6.14.2 and updates ancestor dependency [express](https://github.com/expressjs/express). These dependencies need to be updated together.


Updates `qs` from 6.13.0 to 6.14.2
- [Changelog](https://github.com/ljharb/qs/blob/main/CHANGELOG.md)
- [Commits](ljharb/qs@v6.13.0...v6.14.2)

Updates `express` from 4.21.2 to 4.22.1
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/v4.22.1/History.md)
- [Commits](expressjs/express@4.21.2...v4.22.1)

---
updated-dependencies:
- dependency-name: qs
  dependency-version: 6.14.2
  dependency-type: indirect
- dependency-name: express
  dependency-version: 4.22.1
  dependency-type: direct:production
...

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

Author: dependabot[bot]

backend/package-lock.json

@@ -9,7 +9,7 @@
     "test": "node test.js"
   },
   "dependencies": {
-    "express": "^4.18.2",
+    "express": "^4.22.1",
     "nanoid": "^3.3.7",
     "qrcode": "^1.5.3",
     "cors": "^2.8.5"