Update VM selftests for RHEL9.4

Update VM selftests to introduce new tests, and stabilize failing tests.

JIRA: https://issues.redhat.com/browse/RHEL-5617

Omitted-fix: 4b86316ef182 ("selftests/mm: dont run ksm_functional_tests twice") already resolved

Tested: https://beaker.engineering.redhat.com/jobs/8817543

Signed-off-by: Nico Pache npache@redhat.com