Make tempest plugin sanity job non voting

Tempest plugin sanity job is failing with below
error
- https://zuul.opendev.org/t/openstack/build/2c2ed82bd12948b98d9ea7e2ebe625a8

  from os_ken.tests.integrated.common import quagga
ImportError: cannot import name 'quagga' from 'os_ken.tests.integrated.common'

To unblock the Tempest gate, making it non voting until plugin is fixed.

Change-Id: I2c0f3fa92b4a0ad98698b755b40614a85230756f
diff --git a/zuul.d/project.yaml b/zuul.d/project.yaml
index a7641a6..240af53 100644
--- a/zuul.d/project.yaml
+++ b/zuul.d/project.yaml
@@ -43,7 +43,10 @@
             irrelevant-files: *tempest-irrelevant-files
         - tempest-multinode-full-py3:
             irrelevant-files: *tempest-irrelevant-files
+        # TODO(gmann): make it non voting once failure is fixed in plugin
+        # https://zuul.opendev.org/t/openstack/build/2c2ed82bd12948b98d9ea7e2ebe625a8
         - tempest-tox-plugin-sanity-check:
+            voting: false
             irrelevant-files: &tempest-irrelevant-files-2
               - ^.*\.rst$
               - ^doc/.*$