Bump express from 4.18.3 to 4.19.2 in /functions

Bumps [express](https://github.com/expressjs/express) from 4.18.3 to 4.19.2.
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/master/History.md)
- [Commits](expressjs/express@4.18.3...4.19.2)

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

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

functions/package.json

@@ -20,7 +20,7 @@
   },
   "dependencies": {
     "@google-cloud/storage": "^7.9.0",
-    "express": "^4.18.3",
+    "express": "^4.19.2",
     "firebase-admin": "^12.0.0",
     "firebase-functions": "^4.8.2",
     "moment": "^2.30.1",