e2e(kafka-metadata): the suite leaves its broker PVCs in tenant-root #4641

The kafka-metadata e2e suite (hack/e2e-chainsaw/kafka-metadata/) leaves its broker PVCs behind in tenant-root, about 14 GiB per run: data-0-kafka-kafka-meta-src-* and data-0-kafka-kafka-meta-target-* in the pvcs.txt of nightly run 36659663201. The node pools set deleteClaim: false on purpose, and the walkthrough's cleanup.sh deletes only the applications. It is the same mechanism as #4616 in the kafka suite, and it eats into the replicated-lane pool budget the kubernetes suites check (#4617). Fix shape: delete the PVCs by the strimzi.io/cluster label of both clusters in the suite's cleanup, after the applications are gone, and wait for them.