Add fcst dependency to ocnanalprep (#2728)

Add previous cycle's `fcst` as a dependency to `ocnanalprep`

This ensures that the availability of restart files to the latter. This addresses a
seldomly-encountered race condition where `ocnanalprep` fails due to the
lack of the files.

workflow/rocoto/gfs_tasks.py

@@ -659,7 +659,9 @@ def ocnanalprep(self):
         deps = []
         dep_dict = {'type': 'task', 'name': f'{self.cdump}prepoceanobs'}
         deps.append(rocoto.add_dependency(dep_dict))
-        dependencies = rocoto.create_dependency(dep=deps)
+        dep_dict = {'type': 'task', 'name': 'gdasfcst', 'offset': f"-{timedelta_to_HMS(self._base['cycle_interval'])}"}
+        deps.append(rocoto.add_dependency(dep_dict))
+        dependencies = rocoto.create_dependency(dep_condition='and', dep=deps)
 
         resources = self.get_resource('ocnanalprep')
         task_name = f'{self.cdump}ocnanalprep'