Skip StatelessSecurityGroup tests on xena, yoga and zed branches

Those neutron branches do not support some of the Tobiko
StatelessSecurityGroup tests.

Depends-On: I8ee32ba467bd70142816953598d1736fa353d3d0
Closes-bug: #2045270
Change-Id: I8ab1eb7774e230adf7f6eea27c90978a8b8cf41c

zuul.d/devstack-tobiko-neutron.yaml

@@ -18,6 +18,9 @@
     name: devstack-tobiko-neutron
     parent: devstack-tobiko
     voting: true
+    branches:
+      regex: ^(stable/(xena|yoga|zed)).*$
+      negate: true
     description: |
       Base Tobiko devstack job to execute scenario+faults+scenario test cases.
     vars: &FAULTS_VARS
@@ -34,6 +37,18 @@
       - ^tobiko/tests/unit/
       - ^Vagrantfile
 
+- job:
+    name: devstack-tobiko-neutron
+    parent: devstack-tobiko
+    voting: true
+    branches: ^(stable/(xena|yoga|zed)).*$
+    description: |
+      Base Tobiko devstack job to execute scenario+faults+scenario test cases.
+      Variant applied to stable branches xena, yoga and zed.
+    vars:
+      <<: *FAULTS_VARS
+      pytest_addopts_global: "--skipregex=StatelessSecurityGroup"
+    irrelevant-files: *FAULTS_IRRELEVANT_FILES
 
 # --- OVS jobs----------------------------------------------------------------