chore: add ruby 4.0 support in gh actions

Author: rarruda

.github/workflows/pull_request.yml

@@ -31,6 +31,7 @@ jobs:
         ruby-version:
           - jruby-9.4
           - jruby-10.0
+          - '4.0'
           - 3.4
           - 3.3
           - 3.2

README.md

@@ -13,6 +13,7 @@ Ruby client for the [Unleash](https://github.com/Unleash/unleash) feature manage
 
 ## Supported Ruby interpreters
 
+- MRI 4.0
 - MRI 3.4
 - MRI 3.3
 - MRI 3.2