base-test: fail centos-8 if pointing to centos-8-stream image type

As noted inline, this fails the job if using the centos-8 label (see
If32d0c4c503e11285fdcb7c45188568a5dc010bf) that actually points at a
centos-8-stream node.  This should encourage people to fix the node
usage.

This adds the job to base-test.
I602f2c48fa4845288d72de0cf1d46149815d1cbc adds it to production.

Change-Id: I84fe5bca76884d8f258a292d0814ad43ac7f2be1

playbooks/base-test/pre.yaml

@@ -4,6 +4,29 @@
       zuul_log_path_shard_build: true
     - log-inventory
 
+# NOTE(ianw) 2022-02-09 : centos8 had a hard shutdown at upstream EOL
+# that some were not prepared for.  We can't remove the node-type
+# because that gives a Zuul error, preventing projects merging changes
+# to update their node types (see
+# 2c05c44c32db895d2a793265fb86b6bf662c32d0).  We've removed all the
+# CentOS 8 builds in nodepool and the centos-8 node label is pointing
+# at centos-8-stream.  But to get people moving off this, we fail jobs
+# explicitly using the default nodeset with a name of "centos-8" that
+# points to a image of type "centos-8-stream".
+#
+# This way people can set their jobs non-voting as they merge changes
+# to explicitly move away from centos-8 node type.  We obviously hope
+# to remove this hack ASAP.
+- hosts: all
+  tasks:
+    - name: Fail CentOS 8 nodes
+      fail:
+        msg: "The centos-8 node type is no longer supported.  You need to switch this job to use a centos-8-stream node type."
+      when:
+        - "{{ item }} == 'centos-8'"
+        - "hostvars[item]['nodepool']['label'] == 'centos-8-stream'"
+      loop: "{{ query('inventory_hostnames', 'all,!localhost') }}"
+
 - hosts: all
   pre_tasks:
     # NOTE(pabelanger): Until we hit the validate-host role, we have a minimal