Bump rack from 3.1.5 to 3.1.6 in the dev-dependencies group

Bumps the dev-dependencies group with 1 update: [rack](https://github.com/rack/rack).


Updates `rack` from 3.1.5 to 3.1.6
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@v3.1.5...v3.1.6)

---
updated-dependencies:
- dependency-name: rack
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: dev-dependencies
...

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

Gemfile

@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 gem 'nokogiri'
-gem 'rack', '~> 3.1.5'
+gem 'rack', '~> 3.1.6'
 gem 'rspec'
 gem 'jekyll'
 gem "webrick", "~> 1.8"

Gemfile.lock

@@ -236,7 +236,7 @@ GEM
       forwardable-extended (~> 2.6)
     public_suffix (5.0.5)
     racc (1.8.0)
-    rack (3.1.5)
+    rack (3.1.6)
     rb-fsevent (0.11.2)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
@@ -293,7 +293,7 @@ DEPENDENCIES
   jekyll
   minima
   nokogiri
-  rack (~> 3.1.5)
+  rack (~> 3.1.6)
   rspec
   webrick (~> 1.8)