Remove redundant _old_handlers initialization from __init__ methods

Co-authored-by: bittner <[email protected]>

Author: Copilot

cli_test_helpers/decorators.py

@@ -48,7 +48,6 @@ class ArgvContext(LoggingIsolationMixin):
     def __init__(self, *new_args):
         self._old = sys.argv
         self.args = type(self._old)(new_args)
-        self._old_handlers = None
 
     def __enter__(self):
         self._save_logging_handlers()
@@ -78,7 +77,6 @@ def __init__(self, **kwargs):
             kwargs.pop(key)
 
         super().__init__("os.environ", **kwargs)
-        self._old_handlers = None
 
     def __enter__(self):
         self._save_logging_handlers()
@@ -110,7 +108,6 @@ class RandomDirectoryContext(LoggingIsolationMixin, TemporaryDirectory):
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
-        self._old_handlers = None
 
     def __enter__(self):
         """Create a temporary directory and ``cd`` into it."""