Add Ruby 3.4 support

Author: bastelfreak

README.md

@@ -10,6 +10,7 @@ This action reads your gemspec and provides an output of compatible Ruby version
 A static list of compatible versions is maintained.
 This is a subset of [setup-ruby's supported versions](https://github.com/ruby/setup-ruby#supported-versions).
 
+* 3.4
 * 3.3
 * 3.2
 * 3.1

extract_compatible_ruby_versions

@@ -4,6 +4,7 @@ require 'json'
 require 'rubygems'
 
 VERSIONS = [
+  '3.4',
   '3.3',
   '3.2',
   '3.1',