Wan-AI/Wan2.2-TI2V-5B-Diffusers Image to Video Missing

### Describe the bug

I cannot make it that the 5B version takes in an image and generate a video out of it

```
import torch
import numpy as np
from diffusers import WanPipeline, AutoencoderKLWan, WanTransformer3DModel, UniPCMultistepScheduler
from diffusers.utils import export_to_video, load_image

dtype = torch.bfloat16
device = "cuda"

model_id = "Wan-AI/Wan2.2-TI2V-5B-Diffusers"
vae = AutoencoderKLWan.from_pretrained(model_id, subfolder="vae", torch_dtype=torch.float32)
pipe = WanPipeline.from_pretrained(model_id, vae=vae, torch_dtype=dtype)
pipe.to(device)

height = 704
width = 1280
num_frames = 121
num_inference_steps = 50
guidance_scale = 5.0

prompt = "Two anthropomorphic cats in comfy boxing gear and bright gloves fight intensely on a spotlighted stage."
negative_prompt = "色调艳丽，过曝，静态，细节模糊不清，字幕，风格，作品，画作，画面，静止，整体发灰，最差质量，低质量，JPEG压缩残留，丑陋的，残缺的，多余的手指，画得不好的手部，画得不好的脸部，畸形的，毁容的，形态畸形的肢体，手指融合，静止不动的画面，杂乱的背景，三条腿，背景人很多，倒着走"

output = pipe(
prompt=prompt,
negative_prompt=negative_prompt,
height=height,
width=width,
num_frames=num_frames,
guidance_scale=guidance_scale,
num_inference_steps=num_inference_steps,
).frames[0]
export_to_video(output, "5bit2v_output.mp4", fps=24)

```

It says image is not part of the pipeline

### Reproduction

latest

### Logs

```shell

```

### System Info

latest

### Who can help?

_No response_

Comienza ejecutando el ejemplo proporcionado de WanPipeline con el modelo Wan-AI/Wan2.2-TI2V-5B-Diffusers e inspecciona el punto de entrada de WanPipeline y sus entradas documentadas. Se considera terminado cuando el pipeline 5B acepta una imagen junto con el prompt y produce el vídeo exportado esperado, con cobertura para la ruta image-to-video.

Escrito por el modelo de indexación a partir del texto del issue.