Update twilio-ruby requirement from ~> 5.0 to >= 5, < 8

Updates the requirements on [twilio-ruby](https://github.com/twilio/twilio-ruby) to permit the latest version.
- [Release notes](https://github.com/twilio/twilio-ruby/releases)
- [Changelog](https://github.com/twilio/twilio-ruby/blob/main/CHANGES.md)
- [Commits](twilio/twilio-ruby@5.0.0...7.0.1)

---
updated-dependencies:
- dependency-name: twilio-ruby
  dependency-type: direct:production
...

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

signalwire.gemspec

@@ -37,7 +37,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'vcr', '~> 5.0'
   spec.add_development_dependency 'webmock', '~> 3.5'
 
-  spec.add_dependency 'twilio-ruby', '~> 5.0'
+  spec.add_dependency 'twilio-ruby', '>= 5', '< 8'
   spec.add_dependency 'faye-websocket', '~> 0.11'
   spec.add_dependency 'concurrent-ruby', '~> 1.1'
   spec.add_dependency 'has-guarded-handlers', '~> 1.6.3'