add deprecation warning in data_manager.py

csst_common/data_manager.py

@@ -35,6 +35,8 @@ from .logger import get_logger
 from .params import CSST_PARAMS as CP
 from .time import now
 
+raise DeprecationWarning("DataManager is deprecated and will be no longer available")
+
 
 class CsstMsDataManager:
     """