DPO training issues

[DonStroganotti]

I wanted to give DPO training a try but there seems to be multiple issues with the PairedDataset.

reso and interp are not assigned to self in init but self.reso is being used later in the file

naifu/data/paired_wds.py

Line 54 in af5c34b

"target_size_as_tuple": [(self.reso, self.reso)] * len(original_sizes),

Getting this error when using the default train_dpo.yaml config:

  File "/usr/local/lib/python3.10/dist-packages/torch/utils/data/_utils/worker.py", line 308, in _worker_loop
    data = fetcher.fetch(index)
  File "/usr/local/lib/python3.10/dist-packages/torch/utils/data/_utils/fetch.py", line 51, in fetch
    data = [self.dataset[idx] for idx in possibly_batched_index]
  File "/usr/local/lib/python3.10/dist-packages/torch/utils/data/_utils/fetch.py", line 51, in <listcomp>
    data = [self.dataset[idx] for idx in possibly_batched_index]
  File "/workspace/naifu/data/paired_wds.py", line 63, in __getitem__
    example = self.preprocess_train(example)
  File "/workspace/naifu/data/paired_wds.py", line 33, in preprocess_train
    images = [
  File "/workspace/naifu/data/paired_wds.py", line 34, in <listcomp>
    Image.open(io.BytesIO(im_bytes)).convert("RGB")
TypeError: a bytes-like object is required, not 'int'```

[Mikubill]

Fixed in bf1db75, thanks for the issue!