improve: introduce isort for linting Python imports (#1983)

api/core/entities/provider_entities.py

@@ -1,10 +1,9 @@
 from enum import Enum
 from typing import Optional
 
-from pydantic import BaseModel
-
 from core.model_runtime.entities.model_entities import ModelType
 from models.provider import ProviderQuotaType
+from pydantic import BaseModel
 
 
 class QuotaUnit(Enum):