chore(deps): bump express from 4.19.2 to 4.21.1 in /server

Bumps [express](https://github.com/expressjs/express) from 4.19.2 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@4.19.2...4.21.1)

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

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

server/package.json

@@ -42,7 +42,7 @@
     "discord.js": "^14.16.3",
     "dotenv": "^16.3.1",
     "eslint": "^8.56.0",
-    "express": "^4.19.2",
+    "express": "^4.21.1",
     "express-file-routing": "^3.0.3",
     "express-rate-limit": "^7.4.1",
     "express-validator": "^7.0.1",