[CI] [stable-only] Drop testing on Fedora

The QA/DevStack team does not support testing on Fedora on stable
branches. The fedora-latest nodeset is meant to be used on
master branch only.
This change removes it on this stable branch to allow the nodeset
to progress with Fedora version on master.
In addition, the two Fedora jobs are removed to allow for nodeset
removal.

Change-Id: If952b54bdecf82be811b57f4a17a0c59db54a62a

.zuul.yaml

@@ -68,16 +68,6 @@
         nodes:
           - controller
 
-- nodeset:
-    name: devstack-single-node-fedora-latest
-    nodes:
-      - name: controller
-        label: fedora-32
-    groups:
-      - name: tempest
-        nodes:
-          - controller
-
 - nodeset:
     name: openstack-two-node
     nodes:
@@ -602,23 +592,6 @@
       zuul_copy_output:
         /opt/stack/async: logs
 
-- job:
-    name: devstack-platform-fedora-latest
-    parent: tempest-full-py3
-    description: Fedora latest platform test
-    nodeset: devstack-single-node-fedora-latest
-    voting: false
-
-- job:
-    name: devstack-platform-fedora-latest-virt-preview
-    parent: tempest-full-py3
-    description: Fedora latest platform test using the virt-preview repo.
-    nodeset: devstack-single-node-fedora-latest
-    voting: false
-    vars:
-      devstack_localrc:
-        ENABLE_FEDORA_VIRT_PREVIEW_REPO: true
-
 - job:
     name: devstack-tox-base
     parent: devstack
@@ -691,7 +664,6 @@
       jobs:
         - devstack
         - devstack-ipv6
-        - devstack-platform-fedora-latest
         - devstack-platform-centos-8
         - devstack-platform-bionic
         - devstack-async
@@ -822,4 +794,3 @@
             irrelevant-files:
               - ^.*\.rst$
               - ^doc/.*$
-        - devstack-platform-fedora-latest-virt-preview