chore(deps): bump cookie and express in /backend

Bumps [cookie](https://github.com/jshttp/cookie) to 0.7.1 and updates ancestor dependency [express](https://github.com/expressjs/express). These dependencies need to be updated together.


Updates `cookie` from 0.6.0 to 0.7.1
- [Release notes](https://github.com/jshttp/cookie/releases)
- [Commits](jshttp/cookie@v0.6.0...v0.7.1)

Updates `express` from 4.21.0 to 4.21.1
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/4.21.1/History.md)
- [Commits](expressjs/express@4.21.0...4.21.1)

---
updated-dependencies:
- dependency-name: cookie
  dependency-type: indirect
- dependency-name: express
  dependency-type: direct:production
...

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

backend/package.json

@@ -16,7 +16,7 @@
     "@babel/runtime": "^7.13.10",
     "compression": "^1.7.4",
     "cors": "^2.8.5",
-    "express": "^4.21.0",
+    "express": "^4.21.1",
     "https": "^1.0.0",
     "jose": "^5.2.4",
     "js-yaml": "^4.1.0",