Build(deps-dev): Bump express from 4.21.0 to 4.21.1 (#29134)

Bumps [express](https://github.com/expressjs/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](https://github.com/expressjs/express/compare/4.21.0...4.21.1)

---
updated-dependencies:
- dependency-name: express
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

app/assets/javascripts/custom-proxy/package.json

@@ -18,7 +18,7 @@
   },
   "devDependencies": {
     "clean-base-url": "^1.0.0",
-    "express": "^4.21.0",
+    "express": "^4.21.1",
     "glob": "^10.4.3",
     "html-entities": "^2.5.2",
     "html-rewriter-wasm": "^0.4.1",