The ghcr.io/containerd/registry:2.7 image does not support the ppc64le
architecture, causing the TestCRIImagePullTimeout tests to fail when
executed on a ppc64le device.
Replace the ghcr.io/containerd/registry:2.7 image name and index with
the ghcr.io/containerd/volume-ownership:2.1 image and index in the
HoldingContentOpenWriter test.
Change the image pulled in the NoDataTransferred test to the
ghcr.io/containerd/volume-ownership:2.1 image.
Signed-off-by: James Jenkins <James.Jenkins@ibm.com>