Make stackviz tasks not to fail jobs

Due to issue on stckviz side, job start
failing with POST_FAILURE. If we fix the
issue still we need to wait for periodic job
periodic-package-stackviz-element to publish
the latest tarball on https://tarballs.openstack.org/stackviz/dist/.

Let's not fail the job for any issue occur during
stackviz processing.

Closes-Bug: 1863161

Change-Id: Ifee04f28ecee52e74803f1623aba5cfe5ee5ec90

roles/process-stackviz/tasks/main.yaml

@@ -1,3 +1,6 @@
+- name: Process Stackviz
+  block:
+
   - name: Devstack checks if stackviz archive exists
     stat:
       path: "/opt/cache/files/stackviz-latest.tar.gz"
@@ -55,7 +58,6 @@
       - stackviz_archive.stat.exists
       - subunit_input.stat.exists
       - dstat_input.stat.exists
-  failed_when: False
 
   - name: Run stackviz without dstat
     shell: |
@@ -67,4 +69,5 @@
       - stackviz_archive.stat.exists
       - subunit_input.stat.exists
       - not dstat_input.stat.exists
-  failed_when: False
+
+  ignore_errors: yes