Update irrelevant-files for api/scenario jobs

Adding following neutron source files on which
api/scenario jobs don't need to run:-
- lower-constraints.txt
- sample config files
- fullstack tests
- functional tests
- rally-jobs
- vagrant

Change-Id: I22c73a6ba5dd13163dfb1c48739ef65fb4ba139f
diff --git a/zuul.d/base.yaml b/zuul.d/base.yaml
index 12408ea..81f899a 100644
--- a/zuul.d/base.yaml
+++ b/zuul.d/base.yaml
@@ -83,14 +83,20 @@
               provider_net_base_segm_id: 1
     irrelevant-files:
       - ^(test-|)requirements.txt$
+      - lower-constraints.txt
       - ^releasenotes/.*$
       - ^doc/.*$
+      - ^.*\.conf\.sample$
       - ^setup.cfg$
       - ^.*\.rst$
       - ^neutron/locale/.*$
       - ^neutron/tests/unit/.*$
+      - ^neutron/tests/fullstack/.*
+      - ^neutron/tests/functional/.*
       - ^tools/.*$
       - ^tox.ini$
+      - ^rally-jobs/.*$
+      - ^vagrant/.*$
 
 - job:
     name: neutron-tempest-plugin-scenario