fixed python 3.9 tests

Signed-off-by: aritroCoder <ogcodinggod@gmail.com>

Author: aritroCoder

tests/unit/test_cache.py

@@ -260,21 +260,12 @@ class Person(BaseModel):
     def test_schema_with_many_fields(self) -> None:
         """Verify key generation handles schemas with many fields."""
         # Arrange
-        # Create schema with 50+ fields using proper Pydantic field definition
-        from pydantic import Field
+        # Create schema with 50+ fields using create_model to avoid polluting BaseModel
+        from pydantic import create_model
 
-        fields_dict = {f"field_{i}": (str, Field(default="")) for i in range(60)}
-
-        class LargeSchema(BaseModel):
-            pass
-
-        # Dynamically add fields to the model
-        for field_name, field_type in fields_dict.items():
-            LargeSchema.__annotations__[field_name] = field_type[0]
-            setattr(LargeSchema, field_name, field_type[1])
-
-        # Rebuild model to process the new fields
-        LargeSchema.model_rebuild()
+        # Create a dictionary suitable for create_model
+        fields_dict = {f"field_{i}": (str, ...) for i in range(60)}
+        LargeSchema = create_model("LargeSchema", **fields_dict)  # type: ignore # noqa: N806
 
         prompt = "Generate data"
         model = "llama-3.1-8b-instant"