Bump express and @wp-playground/cli

Bumps [express](https://github.com/expressjs/express) to 4.21.2 and updates ancestor dependency [@wp-playground/cli](https://github.com/WordPress/wordpress-playground). These dependencies need to be updated together.


Updates `express` from 4.19.2 to 4.21.2
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/4.21.2/History.md)
- [Commits](expressjs/express@4.19.2...4.21.2)

Updates `@wp-playground/cli` from 1.0.29 to 1.2.3
- [Changelog](https://github.com/WordPress/wordpress-playground/blob/trunk/CHANGELOG.md)
- [Commits](WordPress/wordpress-playground@v1.0.29...v1.2.3)

---
updated-dependencies:
- dependency-name: express
  dependency-version: 4.21.2
  dependency-type: indirect
- dependency-name: "@wp-playground/cli"
  dependency-version: 1.2.3
  dependency-type: direct:development
...

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

Author: dependabot[bot]