build(deps): bump @web/test-runner-puppeteer from 0.12.1 to 0.15.0

Bumps [@web/test-runner-puppeteer](https://github.com/modernweb-dev/web/tree/HEAD/packages/test-runner-puppeteer) from 0.12.1 to 0.15.0.
- [Release notes](https://github.com/modernweb-dev/web/releases)
- [Changelog](https://github.com/modernweb-dev/web/blob/master/packages/test-runner-puppeteer/CHANGELOG.md)
- [Commits](https://github.com/modernweb-dev/web/commits/@web/[email protected]/packages/test-runner-puppeteer)

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

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