* fix: add o2o field does not create constraint when migrating * Add testcase and update changelog * docs: update migrating list * refactor: use `_handle_o2o_fields` instead of `is_o2o=True` * Remove unused line
* fix: add o2o field does not create constraint when migrating * Add testcase and update changelog * docs: update migrating list * refactor: use `_handle_o2o_fields` instead of `is_o2o=True` * Remove unused line