No bug: [taskgraph] Sort soft-dependencies output to make diffing easier; r=aki

Differential Revision: https://phabricator.services.mozilla.com/D49772

--HG--
extra : moz-landing-system : lando

taskcluster/taskgraph/task.py

@@ -61,7 +61,7 @@ class Task(object):
             'label': self.label,
             'attributes': self.attributes,
             'dependencies': self.dependencies,
-            'soft_dependencies': self.soft_dependencies,
+            'soft_dependencies': sorted(self.soft_dependencies),
             'optimization': self.optimization,
             'task': self.task,
         }