bootstrap: Fix CentOS8 runner
CentOS8 is EOL since December 31, 2021. The packages move to vault.centos.org.
We should migrate to CentOS8 Stream soon.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=15193
Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Alexander Bokovoy <ab@samba.org>
Autobuild-User(master): Andreas Schneider <asn@cryptomilk.org>
Autobuild-Date(master): Thu Feb 3 14:31:01 UTC 2022 on sn-devel-184
[abartlet@samba.org Adapted from commit
0c6554aa0d6812343a8155fca3d7a7993cd5c703
by updating sha1sum]