Bump rack from 2.0.8 to 2.1.4

Bumps [rack](https://github.com/rack/rack) from 2.0.8 to 2.1.4.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/master/CHANGELOG.md)
- [Commits](rack/rack@2.0.8...2.1.4)

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

Author: dependabot[bot]

Gemfile.lock

@@ -1,7 +1,7 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (6.0.3.1)
+    activesupport (6.0.3.2)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
@@ -28,10 +28,10 @@ GEM
     execjs (2.7.0)
     faraday (1.0.1)
       multipart-post (>= 1.2, < 3)
-    ffi (1.12.2)
+    ffi (1.13.1)
     forwardable-extended (2.6.0)
     gemoji (3.0.1)
-    github-pages (205)
+    github-pages (206)
       github-pages-health-check (= 1.16.1)
       jekyll (= 3.8.7)
       jekyll-avatar (= 0.7.0)
@@ -72,15 +72,15 @@ GEM
       mercenary (~> 0.3)
       minima (= 2.5.1)
       nokogiri (>= 1.10.4, < 2.0)
-      rouge (= 3.13.0)
+      rouge (= 3.19.0)
       terminal-table (~> 1.4)
     github-pages-health-check (1.16.1)
       addressable (~> 2.3)
       dnsruby (~> 1.60)
       octokit (~> 4.0)
       public_suffix (~> 3.0)
       typhoeus (~> 1.3)
-    html-pipeline (2.12.3)
+    html-pipeline (2.13.0)
       activesupport (>= 2)
       nokogiri (>= 1.4)
     http_parser.rb (0.6.0)
@@ -212,11 +212,11 @@ GEM
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (3.1.1)
-    rack (2.0.8)
+    rack (2.1.4)
     rb-fsevent (0.10.4)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    rouge (3.13.0)
+    rouge (3.19.0)
     ruby-enum (0.8.0)
       i18n
     rubyzip (2.3.0)
@@ -243,7 +243,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  github-pages (= 205)
+  github-pages (= 206)
   rack
 
 BUNDLED WITH