build: Update bundler requirement to support Ruby 3.2-4.0

Update bundler dependency from ~> 2.2 to >= 2.5 to ensure compatibility
with Ruby 3.2, 3.3, 3.4, and 4.0.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: highb

pathspec.gemspec

@@ -19,7 +19,7 @@ Gem::Specification.new do |s|
   s.homepage = 'https://github.com/highb/pathspec-ruby'
   s.license = 'Apache-2.0'
   s.required_ruby_version = '>= 3.2.0'
-  s.add_development_dependency 'bundler', '~> 2.2'
+  s.add_development_dependency 'bundler', '>= 2.5'
   s.add_development_dependency 'fakefs', '~> 2.5'
   s.add_development_dependency 'kramdown', '~> 2.3'
   s.add_development_dependency 'rake', '~> 13.0'