text: Title: Bug: order of types in openapi spec is not consistent in json rendering
  Body: ### Description
  
  We are seeing the order of types change in openapi generation, which makes comparing golden versions of the openapi spec problematic.  I think the specific problem we are seeing comes from https://github.com/litestar-org/litestar/blob/ffaf5616b19f6f0f4128209c8b49dbcb41568aa2/litestar/_openapi/schema_generation/schema.py#L160 where we use the `set` operation to uniquify the list of types.  The order doesn't matter to the correctness of the openapi spec, so perhaps the responsibility for ensuring a determistic spec file could also come from the serializer, but either way it would be helpful if we could always render the same openapi spec the same way.
  
  ### URL to code causing the issue
  
  _No response_
  
  ### MCVE
  
  ```python
  # Your MCVE code here
  ```
  
  
  ### Steps to reproduce
  
  ```bash
  1. Go to '...'
  2. Click on '....'
  3. Scroll down to '....'
  4. See error
  ```
  
  
  ### Screenshots
  
  _No response_
  
  ### Logs
  
  _No response_
  
  ### Litestar Version
  
  2.9.1
  
  ### Platform
  
  - [ ] Linux
  - [ ] Mac
  - [ ] Windows
  - [ ] Other (Please specify in the description above)