Unable to to create files in binmode.

## Describe the bug

Unable to write binary files. Got `Encoding::UndefinedConversionError: "\x89" from ASCII-8BIT to UTF-8` error.

## To Reproduce

```ruby
Dry::Files.new.write(
  "image.png",
  result[:io].force_encoding(Encoding::BINARY)
)
```

## Expected behavior

Works as `File.binwrite()`
