Bump rack from 1.3.3 to 2.2.14 in /examples/sinatra

Bumps [rack](https://github.com/rack/rack) from 1.3.3 to 2.2.14.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@1.3.3...v2.2.14)

---
updated-dependencies:
- dependency-name: rack
  dependency-version: 2.2.14
  dependency-type: direct:production
...

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

Author: dependabot[bot]

examples/sinatra/Gemfile

@@ -3,4 +3,4 @@ source 'https://rubygems.org'
 gem 'sinatra', '< 4.0'
 gem 'webrick'
 gem "jruby-rack", "~> 1.2"
-gem 'rack', '2.2.8'
+gem 'rack', '2.2.14'

examples/sinatra/Gemfile.lock

@@ -1,12 +1,18 @@
 GEM
-  remote: http://rubygems.org/
+  remote: https://rubygems.org/
   specs:
-    rack (1.3.3)
+    jruby-rack (1.2.4)
+    rack (2.2.14)
     sinatra (1.0)
       rack (>= 1.0)
+    webrick (1.9.1)
 
 PLATFORMS
   java
+  x86_64-linux
 
 DEPENDENCIES
-  sinatra
+  jruby-rack (~> 1.2)
+  rack (= 2.2.14)
+  sinatra (< 4.0)
+  webrick