Update redis requirement from >= 3.0.0, <= 5.1.0 to >= 3.0.0, <= 5.4.0

Updates the requirements on [redis](https://github.com/redis/redis-rb) to permit the latest version.
- [Changelog](https://github.com/redis/redis-rb/blob/master/CHANGELOG.md)
- [Commits](redis/redis-rb@v3.0.0...v5.3.0)

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

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

rate_limit.gemspec

@@ -24,6 +24,6 @@ Gem::Specification.new do |spec|
   spec.require_paths = ['lib']
 
   spec.add_dependency 'activesupport', '>= 5.2', '< 7.3'
-  spec.add_dependency 'redis', '>= 3.0.0', '<= 5.1.0'
+  spec.add_dependency 'redis', '>= 3.0.0', '<= 5.4.0'
   spec.metadata['rubygems_mfa_required'] = 'true'
 end