Remove fedora and centos jobs

The fedora and centos jobs have not been used or maintained for
quite some time. This change removes them and the related notes.

Also removed an outdate note about disabling all the experimental
and periodic jobs.

Change-Id: Ic8eb628e21c49957bdcd10a8d69d850ec921b6d6

zuul.d/jobs.yaml

@@ -141,16 +141,6 @@
     parent: openstack-helm-infra
     nodeset: openstack-helm-ubuntu
 
-- job:
-    name: openstack-helm-infra-centos
-    parent: openstack-helm-infra
-    nodeset: openstack-helm-centos
-
-- job:
-    name: openstack-helm-infra-fedora
-    parent: openstack-helm-infra
-    nodeset: openstack-helm-fedora
-
 - job:
     name: openstack-helm-infra-aio-logging
     parent: openstack-helm-infra-functional
@@ -422,16 +412,6 @@
     parent: openstack-helm-infra
     nodeset: openstack-helm-five-node-ubuntu
 
-- job:
-    name: openstack-helm-infra-five-centos
-    parent: openstack-helm-infra
-    nodeset: openstack-helm-five-node-centos
-
-- job:
-    name: openstack-helm-infra-five-fedora
-    parent: openstack-helm-infra
-    nodeset: openstack-helm-five-node-fedora
-
 - job:
     name: openstack-helm-infra-kubernetes-keystone-auth
     parent: openstack-helm-infra

zuul.d/project.yaml

@@ -44,8 +44,6 @@
     post:
       jobs:
         - publish-openstack-helm-charts
-    # NOTE(srwilkers): Disabling all periodic and experimental jobs until
-    # issues with the kubeadm-aio based deployments are addressed
     periodic:
       jobs:
         - publish-openstack-helm-charts
@@ -54,10 +52,6 @@
         # - openstack-helm-infra-five-ubuntu
     experimental:
       jobs:
-        # NOTE(srwilkers): Disable fedora experimental jobs until issues resolved
-        # - openstack-helm-infra-five-fedora
-        # NOTE(srwilkers): Disable centos experimental jobs until issues resolved
-        # - openstack-helm-infra-five-centos
         # - openstack-helm-infra-five-ubuntu
         - openstack-helm-infra-elastic-beats
         # - openstack-helm-infra-tenant-ceph