Add echgres as a dependency only for RUN=enkfgdas, not enkfgfs (NOAA-EMC#3246)

This PR:
- adds echgres as a dependency only for `RUN=enkfgdas`, not `enkfgfs`
Resolves NOAA-EMC#3244

Author: aerorahul

workflow/rocoto/gfs_tasks.py

@@ -2919,12 +2919,14 @@ def earc(self):
         deps = []
         if 'enkfgdas' in self.run:
             dep_dict = {'type': 'metatask', 'name': f'{self.run}_epmn'}
-        else:
+            deps.append(rocoto.add_dependency(dep_dict))
+            dep_dict = {'type': 'task', 'name': f'{self.run}_echgres'}
+            deps.append(rocoto.add_dependency(dep_dict))
+            dependencies = rocoto.create_dependency(dep_condition='and', dep=deps)
+        else:  # early cycle enkf run (enkfgfs)
             dep_dict = {'type': 'task', 'name': f'{self.run}_esfc'}
-        deps.append(rocoto.add_dependency(dep_dict))
-        dep_dict = {'type': 'task', 'name': f'{self.run}_echgres'}
-        deps.append(rocoto.add_dependency(dep_dict))
-        dependencies = rocoto.create_dependency(dep_condition='and', dep=deps)
+            deps.append(rocoto.add_dependency(dep_dict))
+            dependencies = rocoto.create_dependency(dep=deps)
 
         earcenvars = self.envars.copy()
         earcenvars.append(rocoto.create_envar(name='ENSGRP', value='#grp#'))