build(deps): bump @google-cloud/storage from 6.9.3 to 6.9.4

Bumps [@google-cloud/storage](https://github.com/googleapis/nodejs-storage) from 6.9.3 to 6.9.4.
- [Release notes](https://github.com/googleapis/nodejs-storage/releases)
- [Changelog](https://github.com/googleapis/nodejs-storage/blob/main/CHANGELOG.md)
- [Commits](googleapis/nodejs-storage@v6.9.3...v6.9.4)

---
updated-dependencies:
- dependency-name: "@google-cloud/storage"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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