CentOS Stream 9 and Rocky Linux 9 are no longer supported as host
operating systems or base container images. This also drops all the
related testing in CI.
Note that IPA images still use CentOS Stream 9 until images built on
CentOS Stream 10 are fully validated.
Change-Id: I3f0eccec38c644484ffc27891e844cdf05cb28bd
Signed-off-by: Pierre Riteau <pierre@stackhpc.com>
a6e29d219c