ci: move to d2g worker types (bug 2002720) (#870)

Author: jcristau

.taskcluster.yml

@@ -144,7 +144,7 @@ tasks:
                                     description: 'Created by a [cron task](https://firefox-ci-tc.services.mozilla.com/tasks/${cron.task_id})'
 
                   provisionerId: "${trustDomain}-${level}"
-                  workerType: "decision-gcp"
+                  workerType: "decision"
 
                   tags:
                       $switch:

taskcluster/config.yml

@@ -27,7 +27,7 @@ workers:
             provisioner: 'taskgraph-{level}'
             implementation: docker-worker
             os: linux
-            worker-type: images-gcp
+            worker-type: images
         t-linux:
             provisioner: 'taskgraph-t'
             implementation: docker-worker