Bump express from 4.19.1 to 4.21.0 in the dev-dependencies group

Bumps the dev-dependencies group with 1 update: [express](https://github.com/expressjs/express).


Updates `express` from 4.19.1 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](expressjs/express@4.19.1...4.21.0)

---
updated-dependencies:
- dependency-name: express
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: dev-dependencies
...

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

Author: dependabot[bot]