During the managedcluster-import-controller e2e test, we met the  random issue that the klusterlet CRD and CR are not deleted after the cluster and the manifestWorks are all deleted. 

After debug ,we found the import-controller force deletes the klusterlet-CRD manifestWork, but work-agent did not receive the klusterlet-CRD manifestWork update event to trigger deletion in some cases. 

We decide to add a deleting condition to the manifestWork by the work-agent after watch the manifestWork is deleting.  The import-controller force deletes the klusterlet-CRD manifestWork after the mainfestWork has this deleting condition.