Merge pull request #12143 from tobiasge/fix-missing-s3backend

Fixes #12142: Add S3Backend to __all__

netbox/core/data_backends.py

@@ -20,6 +20,7 @@ from .exceptions import SyncError
 __all__ = (
     'LocalBackend',
     'GitBackend',
+    'S3Backend',
 )
 
 logger = logging.getLogger('netbox.data_backends')