I am using a Pydantic BaseModel with Form() to group form fields together. 
When one of the fields is annotated as `bytes`, FastAPI does not call 
`read()` on the uploaded file and returns a 422 error instead.

What I expect:
- Status 200, FastAPI automatically reads the UploadFile into bytes,
  exactly as it does when `bytes` is a standalone File() parameter.

What actually happens:
- Status 422, `bytes_type` validation error. The raw UploadFile object 
  is passed directly to Pydantic without being read first.

This works fine (standalone):

    @app.post("?url=https%3A%2F%2Fgithub.com%2Fworks%2F")
    async def works(file: bytes = File()):
        return {"size": len(file)}  # ✅ 200

This breaks (inside a Pydantic model):

    class UploadForm(BaseModel):
        file: bytes

    @app.post("?url=https%3A%2F%2Fgithub.com%2Fbreaks%2F")
    async def breaks(data: Annotated[UploadForm, Form()]):
        return {"size": len(data.file)}  # ❌ 422

Affected annotations inside a Pydantic Form model:

| Annotation          | Works? |
|---------------------|--------|
| file: UploadFile    |  Yes |
| file: UploadFile|None | Yes |
| file: list[UploadFile] |  Yes |
| file: bytes         |  No  |
| file: bytes | None  |  No  |
| file: list[bytes]   |  No  |

I looked into the source code. The issue is in `_extract_form_body()` 
in `fastapi/dependencies/utils.py`. The guard:

    isinstance(field_info, params.File)

is always False for fields extracted from a Pydantic model because 
those fields have plain Pydantic FieldInfo, not params.File.
So `read()` is never called on the UploadFile.

I would be happy to work on a fix if this is confirmed.

Windows

0.135.1

### Operating System

Windows

### Operating System Details

Windows 11

### FastAPI Version

0.135.1

### Pydantic Version

2.12.5

### Python Version

Python 3.11.9

### Additional Context