github: Delete cgroup v1 workflows

github: Delete cgroup v1 workflows

Github has deprecated Ubuntu 20.  Since this was the last runner still
running cgroup v1 by default, we no longer have a runner than can run
the automated tests in cgroup v1 mode.  Therefore, delete the cgroup v1
automated test runs.

Note that we'll continue to run them by hand periodically and before
releases, but upstream changes may end up breaking/affecting cgroup v1
support.  We strongly recommend migrating to cgroup v2.

Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>