[ruby/io-console] Filter Ruby engine name rather than just /ruby/

This breaks tests using this path on JRuby because the `jruby`
executable turns into `jjruby` after the sub.

ruby/io-console@e5951aa34c

test/io/console/test_io_console.rb

@@ -462,7 +462,7 @@ def test_sync
     noctty = [EnvUtil.rubybin, "-e", "Process.daemon(true)"]
   when !(rubyw = RbConfig::CONFIG["RUBYW_INSTALL_NAME"]).empty?
     dir, base = File.split(EnvUtil.rubybin)
-    noctty = [File.join(dir, base.sub(/ruby/, rubyw))]
+    noctty = [File.join(dir, base.sub(RUBY_ENGINE, rubyw))]
   end
 
   if noctty