Remove py38-fips jobs because stream8 is dead

The centos project has yanked their entire mirror of stream8:

https://mirror.dfw.rax.opendev.org/centos/8-stream/readme

As such, these jobs can't run at all and thus will block any patches
from landing.

Change-Id: I7b86f9036914dec59db01347ac8a2163e6e9843f
(cherry picked from commit 56da508)

Author: kk7ds

.zuul.yaml

@@ -316,7 +316,6 @@
       - release-notes-jobs-python3
     check:
       jobs:
-        - openstack-tox-functional-py38-fips
         - openstack-tox-functional-py39
         - glance-tox-functional-py39-rbac-defaults
         - glance-ceph-thin-provisioning: