Actually, Ruby 3.3 also warns on this

amatsuda · amatsuda · commit 548a471d8492 · 2024-09-01T15:57:02.000+09:00
diff --git a/Gemfile b/Gemfile
@@ -28,4 +28,4 @@ group :development do
   gem "yui-compressor"
 end
 
-gem "base64" if RUBY_VERSION >= "3.4"
+gem "base64" if RUBY_VERSION >= "3.3"
