e2e: remove snapshot beta CRD mention from the doc
e2e: remove snapshot beta CRD mention from the doc

The snapshot CRD is no longer Beta and this commit adjust the same.

Signed-off-by: Humble Chirammal <dc8ba7e82a7df22725dedec9b10c7aaab9ec713f@redhat.com>

ceph/ceph-csi,ceph/ceph-csi,ceph/ceph-csi,ceph/ceph-csi