text: Title: [BUG] @model_validator(mode="before") issue
  Body: **Describe the bug**
  
  When using something like this, `values` is a `DjangoGetter` instance which is somewhat unexpected to me. Prior to 1.0 and the pydantic update you would get a plain dictionary.
  
  
   
  ```python
  class SomeSchema(Schema):
       somevar:int
  
      @model_validator(mode="before")
      @classmethod
      def foo(cls, values):
          values.get("something")
  ```
  
  **Versions (please complete the following information):**
   - Python version: 3.10
   - Django version: 4.1
   - Django-Ninja version: 1.0.1
   - Pydantic version: 2.5.1
  