[ruby/yarp] Try ignoring $LANG

because the previous commit did not fix it.

https://github.com/ruby/ruby/actions/runs/6054915979/job/16433070185#step:9:155

https://github.com/ruby/yarp/commit/8c9e4c1f15

yarp/templates/template.rb

@@ -340,9 +340,7 @@ if __FILE__ == $0
   if ARGV.empty?
     YARP::TEMPLATES.each { |filepath| YARP.template(filepath) }
   else # ruby/ruby
-    if ENV["LANG"] == "C"
-      Encoding.default_external = Encoding::UTF_8
-    end
+    Encoding.default_external = Encoding::UTF_8
     name, write_to = ARGV
     YARP.template(name, write_to: write_to)
   end