Replace bool.__init__() with __new__() (#4614)

Fixes #4612

stdlib/2/__builtin__.pyi

@@ -871,7 +871,7 @@ class memoryview(Sized, Container[_mv_container_type]):
         def hex(self) -> str: ...
 
 class bool(int):
-    def __init__(self, o: object = ...) -> None: ...
+    def __new__(cls: Type[_T], __o: object = ...) -> _T: ...
     @overload
     def __and__(self, x: bool) -> bool: ...
     @overload

stdlib/2and3/builtins.pyi

@@ -871,7 +871,7 @@ class memoryview(Sized, Container[_mv_container_type]):
         def hex(self) -> str: ...
 
 class bool(int):
-    def __init__(self, o: object = ...) -> None: ...
+    def __new__(cls: Type[_T], __o: object = ...) -> _T: ...
     @overload
     def __and__(self, x: bool) -> bool: ...
     @overload