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

stubs/setuptools/setuptools/sandbox.pyi

@@ -13,7 +13,6 @@ class ExceptionSaver:
 def run_setup(setup_script, args): ...
 
 class AbstractSandbox:
-    def __init__(self) -> None: ...
     def __enter__(self) -> None: ...
     def __exit__(self, exc_type, exc_value, traceback) -> None: ...
     def run(self, func): ...