Fix missing newline at end of CLI migrate file

Added trailing newline to pass flake8 linting requirements.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: abrookins

aredis_om/model/cli/migrate.py

@@ -202,4 +202,4 @@ async def _rollback():
                 err=True,
             )
 
-    run_async(_rollback())
+    run_async(_rollback())