chore: bump version to 5.0.0

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: feanil

auth_backends/__init__.py

@@ -3,4 +3,4 @@
  These package is designed to be used primarily with Open edX Django projects, but should be compatible with non-edX
  projects as well.
 """
-__version__ = '4.6.2'  # pragma: no cover
+__version__ = '5.0.0'  # pragma: no cover