Bump express from 4.16.3 to 4.19.2 in /example/middleware

Bumps [express](https://github.com/expressjs/express) from 4.16.3 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@4.16.3...4.19.2)

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

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

example/middleware/package.json

@@ -4,7 +4,7 @@
     "start": "node server.js"
   },
   "dependencies": {
-    "express": "4.16.3",
+    "express": "4.19.2",
     "express-graphql": "0.6.12",
     "graphql": "14.0.2",
     "graphql-server-hapi": "1.4.1",