♻ Remove media_type from ORJSONResponse as it's inherited from the parent class (#5805)

Co-authored-by: Sebastián Ramírez <tiangolo@gmail.com>

fastapi/responses.py

@@ -27,8 +27,6 @@ class UJSONResponse(JSONResponse):
 
 
 class ORJSONResponse(JSONResponse):
-    media_type = "application/json"
-
     def render(self, content: Any) -> bytes:
         assert orjson is not None, "orjson must be installed to use ORJSONResponse"
         return orjson.dumps(