skip test_tagged_attachment in nova-next

This change adds
tempest.api.compute.servers.test_device_tagging.TaggedAttachmentsTest.test_tagged_attachment
to the tempest exclude regex

over the past few weeks we have noticed this test failing intermitently
and it has not started to become a gate blocker. This test is executed in other
jobs that use the PC machine type and is only failing in the nova-next
job which uses q35. As such while we work out how to address this properly
we skip it in the nova-next.

Conflicts in .zuul.yaml because 5d2f2da changed the same
tempest_exclude_regex and is not in xena.

Change-Id: I845ca5989a8ad84d7c04971316fd892cd29cfe1f
Related-Bug: #1959899
(cherry picked from commit b00ce99)

Author: SeanMooney

.zuul.yaml

@@ -237,7 +237,7 @@
       # tempest_test_exclude_list.
       # FIXME(lyarwood): The tempest.api.compute.admin.test_volume_swap tests
       # are skipped until bug #1929710 is resolved.
-      tempest_exclude_regex: ^tempest\.(scenario\.test_network|api\.compute\.admin\.test_volume_swap)
+      tempest_exclude_regex: ^tempest\.(scenario\.test_network|api\.compute\.admin\.test_volume_swap|api\.compute\.servers\.test_device_tagging\.TaggedAttachmentsTest\.test_tagged_attachment)
       devstack_local_conf:
         post-config:
           $NOVA_CPU_CONF: