Bug 1604749: Get misc worker-type from graph config; r=Callek a=tompr…

…ince DONTBUILD

The original patch calculated the worker type, but didn't use it in the
generated task.

Differential Revision: https://phabricator.services.mozilla.com/D61643

taskcluster/taskgraph/morph.py

@@ -65,8 +65,8 @@ def derive_misc_task(task, purpose, image, taskgraph, label_to_taskid, parameter
     )
 
     task_def = {
-        'provisionerId': 'gecko-t',
-        'workerType': 'misc',
+        'provisionerId': provisioner_id,
+        'workerType': worker_type,
         'dependencies': [task.task_id, image_taskid],
         'created': {'relative-datestamp': '0 seconds'},
         'deadline': task.task['deadline'],