Bump rack from 2.2.5 to 2.2.8

Bumps [rack](https://github.com/rack/rack) from 2.2.5 to 2.2.8.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@v2.2.5...v2.2.8)

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

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

Gemfile.lock

@@ -93,7 +93,7 @@ GEM
       coderay (~> 1.1)
       method_source (~> 1.0)
     racc (1.6.2)
-    rack (2.2.5)
+    rack (2.2.8)
     rack-test (2.0.2)
       rack (>= 1.3)
     rails-dom-testing (2.0.3)