Run CentOS tests on CentOS Stream
Run CentOS tests on CentOS Stream

CentOS 8 went EOL on 2022-01-31. Switch to CentOS Stream 8.

Signed-off-by: Adam Cmiel <1217f9865bd733d1bcad0d0d64be310272c5592c@redhat.com>

projectatomic/atomic-reactor,fr34k8/atomic-reactor,projectatomic/atomic-reactor,fr34k8/atomic-reactor