Bump ws from 8.17.1 to 8.18.0 in /backend

Bumps [ws](https://github.com/websockets/ws) from 8.17.1 to 8.18.0.
- [Release notes](https://github.com/websockets/ws/releases)
- [Commits](https://github.com/websockets/ws/compare/8.17.1...8.18.0)

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

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

backend/package.json

@@ -52,7 +52,7 @@
     "redis": "^4.6.6",
     "socks-proxy-agent": "~7.0.0",
     "typescript": "~4.9.3",
-    "ws": "~8.17.1"
+    "ws": "~8.18.0"
   },
   "devDependencies": {
     "@babel/code-frame": "^7.18.6",