Remove unneeded lines and update mem setup

- Check for "enkfgdas" or "gefs" when NMEM_ENS>=0
for first[last]_mem configuration

Refs NOAA-EMC#2475

jobs/JGLOBAL_STAGE_IC

@@ -3,9 +3,6 @@
 source "${HOMEgfs}/ush/preamble.sh"
 source "${HOMEgfs}/ush/jjob_header.sh" -e "stage_ic" -c "base stage_ic"
 
-# Initialize return code
-err=0
-
 # Execute staging
 "${SCRgfs}/exglobal_stage_ic.py"
 err=$?

ush/python/pygfs/task/stage_ic.py

@@ -32,8 +32,6 @@ def __init__(self, config: Dict[str, Any]) -> None:
         """
         super().__init__(config)
 
-        self.task_config = AttrDict(**self.task_config)
-
     @logit(logger)
     def configure(self, stage_dict: Dict[str, Any]) -> (Dict[str, Any]):
         """Determine stage settings based on configuration and runtime options.
@@ -73,7 +71,7 @@ def configure(self, stage_dict: Dict[str, Any]) -> (Dict[str, Any]):
         stage_dict['rRUN'] = rRUN
 
         # Determine ensemble member settings
-        if self.task_config.NMEM_ENS > 0:  # Ensemble RUN
+        if self.task_config.NMEM_ENS > 0 and self.task_config.RUN in ['enkfgdas', 'gefs']:  # Ensemble RUN
             if self.task_config.RUN == "gefs":
                 stage_dict['first_mem'] = 0
                 stage_dict['last_mem'] = self.task_config.NMEM_ENS