Bump rack from 2.2.3 to 2.2.3.1 in /meta/docker/rzz

Bumps [rack](https://github.com/rack/rack) from 2.2.3 to 2.2.3.1.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](https://github.com/rack/rack/compare/2.2.3...2.2.3.1)

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

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

meta/docker/rzz/Gemfile.lock

@@ -15,7 +15,7 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     racc (1.6.0)
-    rack (2.2.3)
+    rack (2.2.3.1)
     rake (13.0.1)
     rb-fsevent (0.10.3)
     rb-inotify (0.10.1)