Bump @octokit/webhooks from 13.3.0 to 13.4.0

Bumps [@octokit/webhooks](https://github.com/octokit/webhooks.js) from 13.3.0 to 13.4.0.
- [Release notes](https://github.com/octokit/webhooks.js/releases)
- [Commits](octokit/webhooks.js@v13.3.0...v13.4.0)

---
updated-dependencies:
- dependency-name: "@octokit/webhooks"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]