[ruby/json] Always dup argument to preserve original encoding for force_encoding
https://github.com/ruby/json/commit/db9a489ca2
[ruby/json] Always dup argument to preserve original encoding for force_encoding
https://github.com/ruby/json/commit/db9a489ca2