Remove arm64 jobs (temporarily)

ARM64 nodes are currently unavailable, so temporarily remove these
jobs.  Unfortunately due to the auto-generated job listings, we need
to completely remove them, not just comment them out.

To be clear, we should add these back (but possibly in a dedicated
secondary pipeline) when we're able.

Change-Id: I462596dfb47ed88e2ba19e314c075227f6f912ac

zuul-tests.d/container-roles-jobs.yaml

@@ -53,24 +53,6 @@
         - name: ubuntu-xenial
           label: ubuntu-xenial
 
-- job:
-    name: zuul-jobs-test-ensure-docker-ubuntu-bionic-arm64
-    description: Tests ensure-docker role on ubuntu-bionic-arm64
-    parent: zuul-jobs-test-ensure-docker
-    nodeset:
-      nodes:
-        - name: ubuntu-bionic-arm64
-          label: ubuntu-bionic-arm64
-
-- job:
-    name: zuul-jobs-test-ensure-docker-ubuntu-focal-arm64
-    description: Tests ensure-docker role on ubuntu-focal-arm64
-    parent: zuul-jobs-test-ensure-docker
-    nodeset:
-      nodes:
-        - name: ubuntu-focal-arm64
-          label: ubuntu-focal-arm64
-
 - job:
     name: zuul-jobs-test-build-container-image-release
     description: |
@@ -425,8 +407,6 @@
         - zuul-jobs-test-ensure-docker-debian-stretch
         - zuul-jobs-test-ensure-docker-ubuntu-bionic
         - zuul-jobs-test-ensure-docker-ubuntu-xenial
-        - zuul-jobs-test-ensure-docker-ubuntu-bionic-arm64
-        - zuul-jobs-test-ensure-docker-ubuntu-focal-arm64
         - zuul-jobs-test-build-container-image-release
         - zuul-jobs-test-build-docker-image-release
         - zuul-jobs-test-build-docker-image-release-multiarch