build(deps-dev): bump @web/test-runner from 0.18.3 to 0.19.0

Bumps [@web/test-runner](https:/modernweb-dev/web/tree/HEAD/packages/test-runner) from 0.18.3 to 0.19.0.
- [Release notes](https:/modernweb-dev/web/releases)
- [Changelog](https:/modernweb-dev/web/blob/master/packages/test-runner/CHANGELOG.md)
- [Commits](https:/modernweb-dev/web/commits/@web/[email protected]/packages/test-runner)

---
updated-dependencies:
- dependency-name: "@web/test-runner"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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