build(deps): bump chef-utils from 17.8.25 to 17.9.18 in /docs

Bumps [chef-utils](https://github.com/chef/chef) from 17.8.25 to 17.9.18.
- [Release notes](https://github.com/chef/chef/releases)
- [Changelog](https://github.com/chef/chef/blob/main/CHANGELOG.md)
- [Commits](https://github.com/chef/chef/compare/v17.8.25...v17.9.18)

---
updated-dependencies:
- dependency-name: chef-utils
  dependency-type: indirect
  update-type: version-update:semver-minor
...

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

docs/Gemfile.lock

@@ -9,7 +9,7 @@ GEM
       zeitwerk (~> 2.2, >= 2.2.2)
     addressable (2.8.0)
       public_suffix (>= 2.0.2, < 5.0)
-    chef-utils (17.8.25)
+    chef-utils (17.9.18)
       concurrent-ruby
     coffee-script (2.4.1)
       coffee-script-source