chore(deps): bump rack from 2.2.9 to 2.2.18 in /examples/ruby-api

Bumps [rack](https://github.com/rack/rack) from 2.2.9 to 2.2.18.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@v2.2.9...v2.2.18)

---
updated-dependencies:
- dependency-name: rack
  dependency-version: 2.2.18
  dependency-type: indirect
...

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

Author: dependabot[bot]

examples/ruby-api/Gemfile.lock

@@ -8,7 +8,7 @@ GEM
     nio4r (2.7.3)
     puma (5.6.9)
       nio4r (~> 2.0)
-    rack (2.2.9)
+    rack (2.2.18)
     rack-protection (2.2.3)
       rack
     ruby2_keywords (0.0.5)