[npm]: Bump @slack/bolt from 4.1.0 to 4.2.0

Bumps [@slack/bolt](https://github.com/slackapi/bolt-js) from 4.1.0 to 4.2.0.
- [Release notes](https://github.com/slackapi/bolt-js/releases)
- [Commits](https://github.com/slackapi/bolt-js/compare/@slack/[email protected]...@slack/[email protected])

---
updated-dependencies:
- dependency-name: "@slack/bolt"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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