build(deps): bump serve-static and express in /docker/async-slowapp

Bumps [serve-static](https://github.com/expressjs/serve-static) to 2.2.0 and updates ancestor dependency [express](https://github.com/expressjs/express). These dependencies need to be updated together.


Updates `serve-static` from 1.14.1 to 2.2.0
- [Release notes](https://github.com/expressjs/serve-static/releases)
- [Changelog](https://github.com/expressjs/serve-static/blob/master/HISTORY.md)
- [Commits](expressjs/serve-static@v1.14.1...v2.2.0)

Updates `express` from 5.0.0-alpha.8 to 5.1.0
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/master/History.md)
- [Commits](expressjs/express@5.0.0-alpha.8...v5.1.0)

---
updated-dependencies:
- dependency-name: serve-static
  dependency-version: 2.2.0
  dependency-type: indirect
- dependency-name: express
  dependency-version: 5.1.0
  dependency-type: direct:production
...

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Author: dependabot[bot]