Switch TripleO jobs to CentOS 9

With [1] CentOS8 Tripleo Jobs are dropped for
master in favor of CentOS9 jobs and since it merged
periodic pipeline of neutron is not running, switch
to CentOS9 based jobs to fix it.

[1] https://review.opendev.org/c/openstack/tripleo-ci/+/826317

Change-Id: Ic1a5c1ab96d9e33b2158be25e638ed2e3c5aacd5

zuul.d/project.yaml

@@ -97,8 +97,8 @@
             voting: true
         - ironic-tempest-ipa-wholedisk-bios-agent_ipmitool-tinyipa
         - openstacksdk-functional-devstack-networking
-        - tripleo-ci-centos-8-content-provider
-        - neutron-centos-8-tripleo-standalone:
+        - tripleo-ci-centos-9-content-provider
+        - neutron-centos-9-tripleo-standalone:
             voting: true
             vars: &consumer_vars
               consumer_job: true
@@ -106,8 +106,8 @@
               remove_tags:
                 - build
             dependencies: &consumer_deps
-              - tripleo-ci-centos-8-content-provider
-        - neutron-ovn-tripleo-ci-centos-8-containers-multinode:
+              - tripleo-ci-centos-9-content-provider
+        - neutron-ovn-tripleo-ci-centos-9-containers-multinode:
             vars: *consumer_vars
             dependencies: *consumer_deps
         - neutron-linuxbridge-tempest-plugin-scenario-nftables

zuul.d/tripleo.yaml

@@ -1,6 +1,6 @@
 - job:
-    name: neutron-centos-8-tripleo-standalone
-    parent: tripleo-ci-base-standalone-centos-8
+    name: neutron-centos-9-tripleo-standalone
+    parent: tripleo-ci-centos-9-standalone
     voting: false
     branches: ^master$
     vars:
@@ -38,8 +38,8 @@
       - ^zuul.d/(?!(project)).*\.yaml
 
 - job:
-    name: neutron-ovn-tripleo-ci-centos-8-containers-multinode
-    parent: tripleo-ci-centos-8-containers-multinode
+    name: neutron-ovn-tripleo-ci-centos-9-containers-multinode
+    parent: tripleo-ci-centos-9-containers-multinode
     branches: ^master$
     vars:
       nodes: 1ctlr