Change metp dependency (NOAA-EMC#1900)

MET+ jobs rely on files already having been placed in the local
archive directory, but the job only depended on post, resulting
in the job prematurely firing. The dependency is now updated to
be on the archive job instead.

Resolves NOAA-EMC#1756

workflow/rocoto/gfs_tasks.py

@@ -887,7 +887,7 @@ def fit2obs(self):
 
     def metp(self):
         deps = []
-        dep_dict = {'type': 'metatask', 'name': f'{self.cdump}post'}
+        dep_dict = {'type': 'task', 'name': f'{self.cdump}arch'}
         deps.append(rocoto.add_dependency(dep_dict))
         dependencies = rocoto.create_dependency(dep_condition='and', dep=deps)
 
@@ -917,9 +917,6 @@ def arch(self):
         if self.cdump in ['gdas'] and self.app_config.do_fit2obs:
             dep_dict = {'type': 'task', 'name': f'{self.cdump}fit2obs'}
             deps.append(rocoto.add_dependency(dep_dict))
-        if self.app_config.do_metp and self.cdump in ['gfs']:
-            dep_dict = {'type': 'metatask', 'name': f'{self.cdump}metp'}
-            deps.append(rocoto.add_dependency(dep_dict))
         if self.app_config.do_wave:
             dep_dict = {'type': 'task', 'name': f'{self.cdump}wavepostsbs'}
             deps.append(rocoto.add_dependency(dep_dict))