CentOS 7 removal prep changes

This drop min-ready for centos-7 to 0 and removes use of some centos 7
jobs from puppet-midnoet. We will clean up those removed jobs in a
followup change to openstack-zuul-jobs.

We also remove x/collected-openstack-plugins from zuul. This repo uses
centos 7 nodesets that we want to clean up and it last merged a change
in 2019. That change was written by the infra team as part of global
cleanups. I think we can remove it from zuul for now and if interest
restarts it can be added and fixed up.

Change-Id: I06f8b0243d2083aacb44fe12c0c850991ce3ef63

nodepool/nl01.opendev.org.yaml

@@ -16,7 +16,7 @@ zookeeper-servers:
 # another launcher will need to assume this logic.
 labels:
   - name: centos-7
-    min-ready: 1
+    min-ready: 0
   - name: centos-8-stream
     min-ready: 1
   - name: centos-9-stream

zuul.d/projects.yaml

@@ -5387,11 +5387,6 @@
       - openstack-python-jobs
       - publish-to-pypi
 
-- project:
-    name: x/collectd-openstack-plugins
-    templates:
-      - openstack-python-jobs
-
 - project:
     name: x/compass-adapters
     templates:
@@ -6415,37 +6410,10 @@
     name: x/puppet-midonet
     check:
       jobs:
-        - legacy-puppet-midonet-puppet-unit-4.5-centos-7:
-            irrelevant-files:
-              - ^.*\.md$
-              - ^.*\.rst$
-              - ^doc/.*$
-              - ^etc/.*$
-              - ^metadata.json$
-              - ^releasenotes/.*$
-              - ^test-requirements.txt$
-        - legacy-puppet-midonet-puppet-unit-latest-centos-7:
-            voting: false
-            branches: ^master
-            irrelevant-files:
-              - ^.*\.md$
-              - ^.*\.rst$
-              - ^doc/.*$
-              - ^etc/.*$
-              - ^metadata.json$
-              - ^releasenotes/.*$
-              - ^test-requirements.txt$
+        - noop
     gate:
       jobs:
-        - legacy-puppet-midonet-puppet-unit-4.5-centos-7:
-            irrelevant-files:
-              - ^.*\.md$
-              - ^.*\.rst$
-              - ^doc/.*$
-              - ^etc/.*$
-              - ^metadata.json$
-              - ^releasenotes/.*$
-              - ^test-requirements.txt$
+        - noop
 
 - project:
     name: x/puppet-n1k-vsm

zuul/main.yaml

@@ -1148,7 +1148,6 @@
           - x/cloudroast
           - x/coats
           - x/cognitive
-          - x/collectd-openstack-plugins
           - x/compass-adapters
           - x/compass-core
           - x/compass-install