Description of problem:
When garbage collector disabled (TTL set to -1), the data import cron garbage collection won't work.

Version-Release number of selected component (if applicable):
4.12

How reproducible:
100%

Steps to Reproduce:
1. disable garbage collector via hco:
oc patch cdi cdi-kubevirt-hyperconverged --patch '{"spec": {"config":

}}' --type merge`

2. Create a new data import cron with DataImportCron.Spec.ImportsToKeep set to 1

3. wait for the DV to reach success

4. update the image stream digest

5. wait for a new DV to be created

Actual results:
2 DV in success status

Expected results:
once the new DV reach success the old one should be deleted