zuul: add irrelevant-files section to job

This adds the 'irrelevant-files' section to the blazar-devstack-dsvm
job. If all the changes are in this list, the job is not run.

Change-Id: I2de90e7131d726cdadb9bab29c1a155d65e9ed1d

.zuul.yaml

@@ -1,6 +1,14 @@
 - job:
     name: blazar-devstack-dsvm
     parent: legacy-dsvm-base
+    irrelevant-files:
+      - ^.*\.rst$
+      - ^blazar/tests/.*$
+      - ^doc/.*$
+      - ^releasenotes/.*$
+      - ^test-requirements.txt$
+      - ^tools/.*$
+      - ^tox.ini$
     run: playbooks/legacy/blazar-devstack-dsvm/run.yaml
     post-run: playbooks/legacy/blazar-devstack-dsvm/post.yaml
     timeout: 4200
@@ -19,4 +27,3 @@
     gate:
       jobs:
         - blazar-devstack-dsvm
-