build(deps-dev): update rspec requirement from ~> 3.12.0 to ~> 3.13.0

Updates the requirements on [rspec](https://github.com/rspec/rspec-metagem) to permit the latest version.
- [Commits](rspec/rspec-metagem@v3.12.0...v3.13.0)

---
updated-dependencies:
- dependency-name: rspec
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

puppeteer-ruby.gemspec

@@ -30,7 +30,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'pry-byebug'
   spec.add_development_dependency 'rake', '~> 13.1.0'
   spec.add_development_dependency 'rollbar'
-  spec.add_development_dependency 'rspec', '~> 3.12.0'
+  spec.add_development_dependency 'rspec', '~> 3.13.0'
   spec.add_development_dependency 'rspec_junit_formatter' # for CircleCI.
   spec.add_development_dependency 'rubocop', '~> 1.50.0'
   spec.add_development_dependency 'rubocop-rspec'