Merge pull request #1113 from koic/ci_against_ruby_4_0

Run CI against Ruby 4.0

Author: koic

.github/workflows/CI.yml

@@ -15,6 +15,7 @@ jobs:
         ruby:
           # TODO: curb fails on ruby-head. Re-enable ruby-head once fixed.
           # - head
+          - '4.0'
           - '3.4'
           - '3.3'
           - '3.2'

README.md

@@ -45,6 +45,7 @@ Supported Ruby Interpreters
 * MRI 3.2
 * MRI 3.3
 * MRI 3.4
+* MRI 4.0
 * JRuby
 
 ## Installation