Streamline script creating list of ensemble backgrounds (NOAA-EMC#1313)

Co-authored-by: Rahul Mahajan <aerorahul@users.noreply.github.com>

ush/python/pygfs/task/atmens_analysis.py

@@ -252,14 +252,8 @@ def get_bkg_dict(self, task_config: Dict[str, Any]) -> Dict[str, List[str]]:
             basename = f'{to_fv3time(task_config.current_cycle)}.coupler.res'
             bkglist.append([os.path.join(rst_dir, basename), os.path.join(task_config.DATA, 'bkg', memchar, basename)])
             # atmens DA needs core, srf_wnd, tracer, phy_data, sfc_data
-            for ftype in ['core', 'srf_wnd', 'tracer']:
-                template = f'{to_fv3time(self.task_config.current_cycle)}.fv_{ftype}.res.tile{{tilenum}}.nc'
-                for itile in range(1, task_config.ntiles + 1):
-                    basename = template.format(tilenum=itile)
-                    bkglist.append([os.path.join(rst_dir, basename), os.path.join(run_dir, basename)])
-
-            for ftype in ['phy_data', 'sfc_data']:
-                template = f'{to_fv3time(self.task_config.current_cycle)}.{ftype}.tile{{tilenum}}.nc'
+            template = f'{to_fv3time(self.task_config.current_cycle)}.{ftype}.tile{{tilenum}}.nc'
+            for ftype in ['fv_core.res', 'fv_srf_wnd.res', 'fv_tracer.res', 'phy_data', 'sfc_data']:                
                 for itile in range(1, task_config.ntiles + 1):
                     basename = template.format(tilenum=itile)
                     bkglist.append([os.path.join(rst_dir, basename), os.path.join(run_dir, basename)])