Make tempest-tox-plugin-sanity-check n-v

Making tempest-tox-plugin-sanity-check job non-voting
until we fix this issue that makes the job constantly
failing:

https: //bugs.launchpad.net/tempest/+bug/2053026
Change-Id: I1d50b8e81425fa228e03d37a81aaaffdfa5c089c

zuul.d/project.yaml

@@ -44,6 +44,9 @@
         - tempest-multinode-full-py3:
             irrelevant-files: *tempest-irrelevant-files
         - tempest-tox-plugin-sanity-check:
+            # TODO(kopecmartin): non-voting until this is resolved:
+            # https://bugs.launchpad.net/tempest/+bug/2053026
+            voting: false
             irrelevant-files: &tempest-irrelevant-files-2
               - ^.*\.rst$
               - ^doc/.*$