Remove centos-stream-8-x64 from test workflow

Not available on DO anymore

.github/workflows/test.yml

@@ -21,7 +21,6 @@ jobs:
           - ubuntu-24-04-x64
           - fedora-39-x64
           - centos-7-x64
-          - centos-stream-8-x64
           # - centos-stream-9-x64 # yum oomkill
     steps:
       - uses: actions/checkout@v4