[migration tests]: Node pull method for CDI instead of scratch PVCs
[migration tests]: Node pull method for CDI instead of scratch PVCs

Basically a follow up for https://github.com/kubevirt/kubevirt/pull/8318,
Less large PVCs should be around since node pull does not require scratch space.
Also, we are seeing a memory spike over our limits so this can help mitigate too:
https://storage.googleapis.com/kubevirt-prow/reports/flakefinder/kubevirt/kubevirt/flakefinder-2022-10-31-168h.html#row2

Signed-off-by: Alex Kalenyuk <77578c3ce491cadaffe9b225ce72d2389064bf43@redhat.com>

kubevirt/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt