Bump rack from 2.2.4 to 2.2.8.1

Bumps [rack](https://github.com/rack/rack) from 2.2.4 to 2.2.8.1.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@2.2.4...v2.2.8.1)

---
updated-dependencies:
- dependency-name: rack
  dependency-type: direct:production
...

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

Gemfile

@@ -29,7 +29,7 @@ gem 'loog', '0.5.1'
 gem 'minitest', '5.21.2', require: false
 gem 'minitest-reporters', '1.6.1', require: false
 gem 'pgtk', '0.9.2'
-gem 'rack', '2.2.4'
+gem 'rack', '2.2.8.1'
 gem 'rack-ssl', '1.4.1'
 gem 'rack-test', '2.1.0'
 gem 'rake', '13.1.0', require: false

Gemfile.lock

@@ -138,7 +138,7 @@ GEM
     psych (5.1.2)
       stringio
     racc (1.7.3)
-    rack (2.2.4)
+    rack (2.2.8.1)
     rack-protection (3.2.0)
       base64 (>= 0.1.0)
       rack (~> 2.2, >= 2.2.4)
@@ -296,7 +296,7 @@ DEPENDENCIES
   minitest (= 5.21.2)
   minitest-reporters (= 1.6.1)
   pgtk (= 0.9.2)
-  rack (= 2.2.4)
+  rack (= 2.2.8.1)
   rack-ssl (= 1.4.1)
   rack-test (= 2.1.0)
   rake (= 13.1.0)