ticdc: pvc_cleaner doesn't reclaim PVC after ticdc scaled in

[mahjonp]

Bug Report

https://github.com/pingcap/tidb-operator/blob/b004b9aa02197d7198d7fa44c5fee3958dd07dd6/pkg/manager/member/pvc_cleaner.go#L71-L103

What did you do?

Create a tidb-cluster with 3 ticdc replicas, then scale in 1 replicas

What did you expect to see?

Only 1 ticdc data pvc left.

In our k8s environment, the storageclass we use is extremely valuable. Each node has only 2-3 PVs created, yet we run hundreds of TiDB clusters for testing purposes. Therefore, it is imperative that scaled-in PVs are reclaimed as soon as possible.

What did you see instead?

ticdc-data-tc-ticdc-0      Bound    pvc-8d6d669a-c631-40da-9c14-dd108825b331   500Gi      RWO            local-path     11m
ticdc-data-tc-ticdc-1      Bound    pvc-53e1eeee-bab5-4d48-a3a9-ab91fb4c4111   500Gi      RWO            local-path     11m
ticdc-data-tc-ticdc-2      Bound    pvc-e61a2b51-7b71-421b-820a-81ae2d2e20fb   500Gi      RWO            local-path     11m