Update puma requirement from ~> 3.11.4 to >= 3.11.4, < 6.5.0

Updates the requirements on [puma](https://github.com/puma/puma) to permit the latest version.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v3.11.4...v6.4.2)

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

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

oxidized-web.gemspec

@@ -21,7 +21,7 @@ Gem::Specification.new do |s|
   s.add_runtime_dependency 'haml',                '~> 5.0'
   s.add_runtime_dependency 'htmlentities',        '~> 4.3'
   s.add_runtime_dependency 'oxidized',            '~> 0.26'
-  s.add_runtime_dependency 'puma',                '~> 3.11.4'
+  s.add_runtime_dependency 'puma',                '>= 3.11.4', '< 6.5.0'
   s.add_runtime_dependency 'sass',                '~> 3.3'
   s.add_runtime_dependency 'sinatra',             '~> 1.4', '>= 1.4.6'
   s.add_runtime_dependency 'sinatra-contrib',     '~> 1.4', '>= 1.4.6'