[wip][lora]feat: use exclude modules to loraconfig.

[sayakpaul]

What does this PR do?

If we try to do:

from diffusers import AutoModel, DiffusionPipeline 
import torch

model_id = "Wan-AI/Wan2.1-VACE-14B-diffusers"
vae = AutoModel.from_pretrained(model_id, subfolder="vae", torch_dtype=torch.float32)
pipe = DiffusionPipeline.from_pretrained(model_id, vae=vae, torch_dtype=torch.bfloat16).to("cuda")
pipe.load_lora_weights(
   "vrgamedevgirl84/Wan14BT2VFusioniX", 
   weight_name="FusionX_LoRa/Wan2.1_T2V_14B_FusionX_LoRA.safetensors",
)

It prints:

Unfold

Loading adapter weights from state_dict led to missing keys in the model: vace_blocks.0.proj_out.lora_A.default_0.weight, vace_blocks.0.proj_out.lora_B.default_0.weight, vace_blocks.1.proj_out.lora_A.default_0.weight, vace_blocks.1.proj_out.lora_B.default_0.weight, vace_blocks.2.proj_out.lora_A.default_0.weight, vace_blocks.2.proj_out.lora_B.default_0.weight, vace_blocks.3.proj_out.lora_A.default_0.weight, vace_blocks.3.proj_out.lora_B.default_0.weight, vace_blocks.4.proj_out.lora_A.default_0.weight, vace_blocks.4.proj_out.lora_B.default_0.weight, vace_blocks.5.proj_out.lora_A.default_0.weight, vace_blocks.5.proj_out.lora_B.default_0.weight, vace_blocks.6.proj_out.lora_A.default_0.weight, vace_blocks.6.proj_out.lora_B.default_0.weight, vace_blocks.7.proj_out.lora_A.default_0.weight, vace_blocks.7.proj_out.lora_B.default_0.weight.

It happens because target_modules in LoraConfig treats the values in target_modules as suffixes. In this case, proj_out is a part of target_modules which is why vace_blocks_* get targeted here (and hence the missing warning).

LoraConfig allows us to specify exclude_modules, too. This PR introduces support to add it when initializing the LoraConfig.

@apolinario does it work for you?