Bump express from 4.20.0 to 4.21.0 (#6659)

Bumps [express](https://github.com/expressjs/express) from 4.20.0 to 4.21.0.
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/4.21.0/History.md)
- [Commits](https://github.com/expressjs/express/compare/4.20.0...4.21.0)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

src/package.json

@@ -38,7 +38,7 @@
     "cross-spawn": "^7.0.3",
     "ejs": "^3.1.10",
     "esbuild": "^0.23.1",
-    "express": "4.20.0",
+    "express": "4.21.0",
     "express-rate-limit": "^7.4.0",
     "fast-deep-equal": "^3.1.3",
     "find-root": "1.1.0",