pylint: Fix useless-object-inheritance

https://pylint.pycqa.org/en/latest/user_guide/messages/refactor/useless-object-inheritance.html:
> Used when a class inherit from object, which under python3 is
implicit, hence can be safely removed from bases.

Fixes: https://pagure.io/freeipa/issue/9278
Signed-off-by: Stanislav Levin <slev@altlinux.org>
Reviewed-By: Stanislav Levin <slev@altlinux.org>

ipapython/install/core.py

@@ -58,7 +58,7 @@ class KnobValueError(ValueError):
         self.name = name
 
 
-class PropertyBase(six.with_metaclass(util.InnerClassMeta, object)):
+class PropertyBase(metaclass=util.InnerClassMeta):
     # shut up pylint
     __outer_class__ = None
     __outer_name__ = None
@@ -227,7 +227,7 @@ def extend_knob(base, default=_missing, bases=_missing, group=_missing,
     )
 
 
-class Configurable(six.with_metaclass(abc.ABCMeta, object)):
+class Configurable(metaclass=abc.ABCMeta):
     """
     Base class of all configurables.
 
@@ -487,7 +487,7 @@ class ComponentMeta(util.InnerClassMeta, abc.ABCMeta):
     pass
 
 
-class ComponentBase(six.with_metaclass(ComponentMeta, Configurable)):
+class ComponentBase(Configurable, metaclass=ComponentMeta):
     # shut up pylint
     __outer_class__ = None
     __outer_name__ = None

ipapython/install/typing.py

@@ -4,7 +4,6 @@
 
 import weakref
 
-import six
 
 _cache = weakref.WeakValueDictionary()
 
@@ -27,7 +26,7 @@ class ListMeta(type):
         return _cache.get(key, t)
 
 
-class List(six.with_metaclass(ListMeta, list)):
+class List(list, metaclass=ListMeta):
     __parameters__ = ()
 
     def __init__(self, *_args, **_kwargs):