Merge pull request #872 from javan/ci-ruby-4.0

CI: Add Ruby 4.0 to CI Matrix

Author: taketo1113

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest]
-        ruby-version: [ '2.4', '2.5', '2.6', '2.7', '3.0', '3.0', '3.2', '3.3', '3.4', 'jruby-9', 'jruby-10']
+        ruby-version: [ '2.4', '2.5', '2.6', '2.7', '3.0', '3.0', '3.2', '3.3', '3.4', '4.0', 'jruby-9', 'jruby-10']
         # CRuby < 2.6 does not support macos-arm64, so test those on amd64 instead
         exclude:
           - os: macos-latest
@@ -42,7 +42,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: ['2.7', '3.0', '3.0', '3.2', '3.3', '3.4']
+        ruby-version: ['2.7', '3.0', '3.0', '3.2', '3.3', '3.4', '4.0']
         rails-version: ['6.0', '6.1', '7.0', '7.1', '7.2', '8.0', '8.1']
         include:
           - ruby-version: 2.7