Update DataImportCron of Fedora to latest tag (#2027)

A latest tag for the Fedora containerdisk was added in [1]. Use that
instead of explicitly specifying a version tag to be always up to date.

[1] kubevirt/containerdisks@db30dfc

Signed-off-by: Felix Matouschek <fmatouschek@redhat.com>

Co-authored-by: Felix Matouschek <fmatouschek@redhat.com>

assets/dataImportCronTemplates/dataImportCronTemplates.yaml

@@ -36,7 +36,7 @@
       spec:
         source:
           registry:
-            url: docker://quay.io/containerdisks/fedora:35
+            url: docker://quay.io/containerdisks/fedora:latest
         storage:
           resources:
             requests: