Improve explanation in code comment

src/pyproject_hooks/_impl.py

@@ -24,7 +24,7 @@ class BackendUnavailable(Exception):
  """Will be raised if the backend cannot be imported in the hook process."""
 
  def __init__(self, traceback, message=None, backend_name=None, backend_path=None):
- # Keep API backward compatibility
+ # Preserving arg order for the sake of API backward compatibility.
  self.backend_name = backend_name
  self.backend_path = backend_path
  self.traceback = traceback