Flux.2-klein-4b lora support

[christopher5106]

Describe the bug

Not sure about the origin of this lora (fal trainer?)

Reproduction

import torch
from diffusers import Flux2KleinPipeline

pipe = Flux2KleinPipeline.from_pretrained("black-forest-labs/FLUX.2-klein-4b", torch_dtype=torch.bfloat16)
pipe.load_lora_weights(
    "fal/flux-2-klein-4b-spritesheet-lora", weight_name="flux-spritesheet-lora.safetensors",
)

Logs

No LoRA keys associated to Flux2Transformer2DModel found with the prefix='transformer'. This is safe to ignore if LoRA state dict didn't originally have any Flux2Transformer2DModel related params. You can also try specifying `prefix=None` to resolve the warning. Otherwise, open an issue if you think it's unexpected: https://github.com/huggingface/diffusers/issues/new

System Info

Diffusers version from today 6875490

Who can help?

@sayakpaul