Remove empty __init__ methods from classes with 0 parents (#8907)

stubs/vobject/vobject/base.pyi

@@ -133,7 +133,6 @@ def defaultSerialize(obj, buf, lineLength): ...
 
 class Stack:
     stack: Any
-    def __init__(self) -> None: ...
     def __len__(self): ...
     def top(self): ...
     def topName(self): ...

stubs/vobject/vobject/behavior.pyi

@@ -12,7 +12,6 @@ class Behavior:
     allowGroup: bool
     forceUTC: bool
     sortFirst: Any
-    def __init__(self) -> None: ...
     @classmethod
     def validate(cls, obj, raiseException: bool = ..., complainUnrecognized: bool = ...): ...
     @classmethod