deps(example): Bump express

Bumps the dependencies group in /examples/nodejs-express-validate-email with 1 update: [express](https://github.com/expressjs/express).


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: express
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: dependencies
...

Signed-off-by: dependabot[bot] <[email protected]>

examples/nodejs-express-validate-email/package.json

@@ -6,7 +6,7 @@
   },
   "dependencies": {
     "@arcjet/node": "file:../../arcjet-node",
-    "express": "^4.21.0"
+    "express": "^4.21.1"
   },
   "devDependencies": {
     "@types/node": "^20",