chore: add ruby 4.0 support in gh actions

- Add ostruct as explicit dependency as required by ruby >= 4.0

Author: rarruda

.github/workflows/pull_request.yml

@@ -30,6 +30,7 @@ jobs:
           - windows
         ruby-version:
           - jruby-9.4
+          - '4.0'
           - 3.4
           - 3.3
           - 3.2

README.md

@@ -15,6 +15,7 @@ You can use this client with [Unleash Enterprise](https://www.getunleash.io/pric
 
 ## Supported Ruby interpreters
 
+- MRI 4.0
 - MRI 3.4
 - MRI 3.3
 - MRI 3.2

unleash-client.gemspec

@@ -28,6 +28,7 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency "base64", "~> 0.3.0"
   spec.add_dependency "logger", "~> 1.6"
+  spec.add_dependency "ostruct", "~> 0.1"
 
   spec.add_development_dependency "rake", "~> 12.3"
   spec.add_development_dependency "rspec", "~> 3.12"