fixed bad import

Author: Andrei Neagu

services/dynamic-scheduler/src/simcore_service_dynamic_scheduler/services/generic_scheduler/__init__.py

@@ -10,6 +10,7 @@
     get_step_group_proxy,
     get_step_store_proxy,
 )
+from ._errors import NoDataFoundError
 from ._event_after_registration import (
     register_to_start_after_on_executed_completed,
     register_to_start_after_on_reverted_completed,
@@ -30,7 +31,6 @@
     SingleStepGroup,
 )
 from ._store import (
-    NoDataFoundError,
     OperationContextProxy,
     StepGroupProxy,
     StepStoreProxy,