Bump sinatra from 3.2.0 to 4.1.0 in /server

Bumps [sinatra](https://github.com/sinatra/sinatra) from 3.2.0 to 4.1.0.
- [Changelog](https://github.com/sinatra/sinatra/blob/main/CHANGELOG.md)
- [Commits](sinatra/sinatra@v3.2.0...v4.1.0)

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

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

Author: dependabot[bot]

server/Gemfile

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 source 'https://rubygems.org'
 
-gem 'sinatra', '>= 3.0.0', '< 4'
+gem 'sinatra', '>= 3.0.0', '< 5'
 gem 'sinatra-websocket', '~> 0.3.1'
 gem 'base64', '~> 0.2.0'

server/Gemfile.lock

@@ -9,27 +9,33 @@ GEM
       addressable (>= 2.1.1)
       eventmachine (>= 0.12.9)
     eventmachine (1.2.7)
+    logger (1.6.1)
     mustermann (3.0.3)
       ruby2_keywords (~> 0.0.1)
     public_suffix (6.0.1)
-    rack (2.2.10)
-    rack-protection (3.2.0)
+    rack (3.1.8)
+    rack-protection (4.1.0)
       base64 (>= 0.1.0)
-      rack (~> 2.2, >= 2.2.4)
+      logger (>= 1.6.0)
+      rack (>= 3.0.0, < 4)
+    rack-session (2.0.0)
+      rack (>= 3.0.0)
     ruby2_keywords (0.0.5)
-    sinatra (3.2.0)
+    sinatra (4.1.0)
+      logger (>= 1.6.0)
       mustermann (~> 3.0)
-      rack (~> 2.2, >= 2.2.4)
-      rack-protection (= 3.2.0)
+      rack (>= 3.0.0, < 4)
+      rack-protection (= 4.1.0)
+      rack-session (>= 2.0.0, < 3)
       tilt (~> 2.0)
     sinatra-websocket (0.3.1)
       em-websocket (~> 0.3.6)
       eventmachine
       thin (>= 1.3.1, < 2.0.0)
-    thin (1.8.2)
-      daemons (~> 1.0, >= 1.0.9)
-      eventmachine (~> 1.0, >= 1.0.4)
-      rack (>= 1, < 3)
+    thin (1.6.2)
+      daemons (>= 1.0.9)
+      eventmachine (>= 1.0.0)
+      rack (>= 1.0.0)
     tilt (2.4.0)
 
 PLATFORMS
@@ -38,7 +44,7 @@ PLATFORMS
 
 DEPENDENCIES
   base64 (~> 0.2.0)
-  sinatra (>= 3.0.0, < 4)
+  sinatra (>= 3.0.0, < 5)
   sinatra-websocket (~> 0.3.1)
 
 BUNDLED WITH