Test with Ruby 3.4

Author: janko

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ["ruby-2.5", "ruby-2.6", "ruby-2.7", "ruby-3.0", "ruby-3.1", "ruby-3.2", "ruby-3.3", "jruby-9.4"]
+        ruby: ["ruby-2.5", "ruby-2.6", "ruby-2.7", "ruby-3.0", "ruby-3.1", "ruby-3.2", "ruby-3.3", "ruby-3.4", "jruby-9.4"]
 
     steps:
       - uses: actions/checkout@v2