Request support for MAGI-1

### Model/Pipeline/Scheduler description

MAGI-1 is a video generation model that has achieved stunning visual effects.

### Open source status

- [x] The model implementation is available.
- [x] The model weights are available (Only relevant if addition is not a scheduler).

### Provide useful links for the implementation

https://github.com/SandAI-org/MAGI-1
https://github.com/SandAI-org/MagiAttention

Start by reading the Diffusers repository description and the linked MAGI-1 and MagiAttention implementations to understand the model and its attention dependency. Confirm the integration requirements from those sources, then add MAGI-1 support so the model implementation and available weights can be used through Diffusers.

Scritto dal modello di indicizzazione a partire dal testo della issue.