Close the tree (#12268)

This will have to be landed on red since it's intended to make the tree red. It can be reverted once we've resolved the ongoing regression preventing the engine->framework roll.

.cirrus.yml

 gcp_credentials: ENCRYPTED[987a78af29b91ce8489594c9ab3fec21845bbe5ba68294b8f6def3cf0d380830f06687a89ea69c87344c5ade369700fe]
 
+fail_task:
+  gke_container:
+   image: gcr.io/flutter-cirrus/build-engine-image:latest
+   cluster_name: build-32-cluster
+   zone: us-central1-a
+   namespace: default
+  fail_script: exit -1
+
 # LINUX
 task:
   gke_container: