Bump puppeteer from 20.3.0 to 20.4.0 in /webdriver (web-platform-test…

…s#3338)

Bumps [puppeteer](https://github.com/puppeteer/puppeteer) from 20.3.0 to 20.4.0.
- [Release notes](https://github.com/puppeteer/puppeteer/releases)
- [Changelog](https://github.com/puppeteer/puppeteer/blob/main/release-please-config.json)
- [Commits](puppeteer/puppeteer@puppeteer-v20.3.0...puppeteer-v20.4.0)

---
updated-dependencies:
- dependency-name: puppeteer
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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