Bump rack from 2.2.6.2 to 2.2.9 in /config/examples/connect_backend_ruby

Bumps [rack](https://github.com/rack/rack) from 2.2.6.2 to 2.2.9.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@v2.2.6.2...v2.2.9)

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

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

config/examples/connect_backend_ruby/Gemfile.lock

@@ -7,7 +7,7 @@ GEM
     nio4r (2.5.8)
     puma (6.0.0)
       nio4r (~> 2.0)
-    rack (2.2.6.2)
+    rack (2.2.9)
     rack-protection (3.0.4)
       rack
     ruby2_keywords (0.0.5)