Update sinatra requirement from ~> 2.2 to ~> 4.1 in the bundler group

Updates the requirements on [sinatra](https://github.com/sinatra/sinatra) to permit the latest version.

Updates `sinatra` to 4.1.0
- [Changelog](https://github.com/sinatra/sinatra/blob/main/CHANGELOG.md)
- [Commits](sinatra/sinatra@v2.2.0...v4.1.0)

---
updated-dependencies:
- dependency-name: sinatra
  dependency-type: direct:development
  dependency-group: bundler
...

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

Author: dependabot[bot]

omniauth-microsoft_graph.gemspec

@@ -21,7 +21,7 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency 'jwt', '~> 2.0'
   spec.add_runtime_dependency 'omniauth', '~> 2.0'
   spec.add_runtime_dependency 'omniauth-oauth2', '~> 1.8.0'
-  spec.add_development_dependency "sinatra", '~> 2.2'
+  spec.add_development_dependency "sinatra", '~> 4.1'
   spec.add_development_dependency "rake", '~> 12.3.3', '>= 12.3.3'
   spec.add_development_dependency 'rspec', '~> 3.6'
   spec.add_development_dependency "mocha", '~> 0'