ci: remove centos-steam-8 customer runner

This broke since eef0bae (migration: Remove block migration) but
even after that was addressed it still fails to complete. As it will
shortly be EOL lets to remove the runner definition and the related
ansible setup bits.

We still have centos9 docker images build and test.

Reviewed-by: Richard Henderson <[email protected]>
Signed-off-by: Alex Bennée <[email protected]>
Message-Id: <[email protected]>

Author: stsquad

.gitlab-ci.d/custom-runners.yml

@@ -32,4 +32,3 @@ include:
   - local: '/.gitlab-ci.d/custom-runners/ubuntu-22.04-s390x.yml'
   - local: '/.gitlab-ci.d/custom-runners/ubuntu-22.04-aarch64.yml'
   - local: '/.gitlab-ci.d/custom-runners/ubuntu-22.04-aarch32.yml'
-  - local: '/.gitlab-ci.d/custom-runners/centos-stream-8-x86_64.yml'

.gitlab-ci.d/custom-runners/centos-stream-8-x86_64.yml

@@ -182,13 +182,6 @@ If you've got access to an IBM Z host that can be used as a gitlab-CI
 runner, you can set this variable to enable the tests that require this
 kind of host. The runner should be tagged with "s390x".
 
-CENTOS_STREAM_8_x86_64_RUNNER_AVAILABLE
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-If you've got access to a CentOS Stream 8 x86_64 host that can be
-used as a gitlab-CI runner, you can set this variable to enable the
-tests that require this kind of host. The runner should be tagged with
-both "centos_stream_8" and "x86_64".
-
 CCACHE_DISABLE
 ~~~~~~~~~~~~~~
 The jobs are configured to use "ccache" by default since this typically