Fix neutron-tempest-linuxbridge irrelevant-files

Change Ibce77d3442e21bbd5f5ce379c203542f1f31ce9e regressed
the irrelevant-files section of the neutron-tempest-linuxbridge
job which makes it run on all code changes to nova. When we
added the job to nova's check queue runs, we specifically
wanted to minimize its use to only changes in the nova/network
and libvirt/vif modules. This fixes the regression by putting
back the old irrelevant-files for that job and leaving a note
for future reviewers.

Change-Id: I00ec0282fce1a05fd314fd34bf429416a3cc9ace

.zuul.yaml

@@ -178,7 +178,25 @@
         - neutron-grenade-multinode:
             irrelevant-files: *dsvm-irrelevant-files
         - neutron-tempest-linuxbridge:
-            irrelevant-files: *dsvm-irrelevant-files
+            irrelevant-files:
+              # NOTE(mriedem): This job has its own irrelevant-files section
+              # so that we only run it on changes to networking and libvirt/vif
+              # code; we don't need to run this on all changes, nor do we run
+              # it in the gate.
+              - ^(?!nova/network/.*)(?!nova/virt/libvirt/vif.py).*$
+              - ^(placement-)?api-.*$
+              - ^(test-|)requirements.txt$
+              - ^.*\.rst$
+              - ^.git.*$
+              - ^doc/.*$
+              - ^nova/hacking/.*$
+              - ^nova/locale/.*$
+              - ^nova/tests/.*$
+              - ^releasenotes/.*$
+              - ^setup.cfg$
+              - ^tests-py3.txt$
+              - ^tools/.*$
+              - ^tox.ini$
         - nova-cells-v1
         - nova-live-migration
         - nova-lvm