Bump serve-static, browser-sync and express

Bumps [serve-static](https://github.com/expressjs/serve-static) to 1.16.2 and updates ancestor dependencies [serve-static](https://github.com/expressjs/serve-static), [browser-sync](https://github.com/BrowserSync/browser-sync) and [express](https://github.com/expressjs/express). These dependencies need to be updated together.


Updates `serve-static` from 1.15.0 to 1.16.2
- [Release notes](https://github.com/expressjs/serve-static/releases)
- [Changelog](https://github.com/expressjs/serve-static/blob/v1.16.2/HISTORY.md)
- [Commits](expressjs/serve-static@v1.15.0...v1.16.2)

Updates `browser-sync` from 2.29.3 to 3.0.3
- [Release notes](https://github.com/BrowserSync/browser-sync/releases)
- [Changelog](https://github.com/BrowserSync/browser-sync/blob/master/changelog.js)
- [Commits](BrowserSync/browser-sync@v2.29.3...v3.0.3)

Updates `express` from 4.18.2 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](expressjs/express@4.18.2...4.21.1)

---
updated-dependencies:
- dependency-name: serve-static
  dependency-type: indirect
- dependency-name: browser-sync
  dependency-type: direct:development
- dependency-name: express
  dependency-type: indirect
...

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