zuul: Drop openstack-tox-functional-py38-fips job

The openstack-tox-functional-py38-fips job is based on centos-8-stream,
which is no longer working and will soon be dropped completely, so
remove the job.

Change-Id: Ie419f2cf9f685bba770b6b2c88571e41758cb212
(cherry picked from commit 726b186)

Author: osfrickler

.zuul.yaml

@@ -371,8 +371,6 @@
       - release-notes-jobs-python3
     check:
       jobs:
-        - openstack-tox-functional-py38-fips:
-            voting: false
         - openstack-tox-functional-py39
         - openstack-tox-functional-py310
         - glance-tox-functional-py39-rbac-defaults