ci: make ci happy lint the code, delete unused imports

Signed-off-by: yihong0618 <zouzou0208@gmail.com>

pilot/singleton.py

@@ -5,10 +5,12 @@
 import abc
 from typing import Any
 
+
 class Singleton(abc.ABCMeta, type):
-    """ Singleton metaclass for ensuring only one instance of a class"""
+    """Singleton metaclass for ensuring only one instance of a class"""
 
     _instances = {}
+
     def __call__(cls, *args: Any, **kwargs: Any) -> Any:
         """Call method for the singleton metaclass"""
         if cls not in cls._instances:
@@ -18,4 +20,5 @@ class Singleton(abc.ABCMeta, type):
 
 class AbstractSingleton(abc.ABC, metaclass=Singleton):
     """Abstract singleton class for ensuring only one instance of a class"""
-    pass
+
+    pass