blank volume snapshots list

### problem

After deleting a VM I noticed that there was still a volume snapshot of the deleted VM so I tried to delete the volume snapshot too but it failed.
Now when I click on "Volume Snapshots" the following error is displayed:
> Cannot invoke "com.cloud.storage.VolumeVO.getRemoved()" because "volumeVO" is null

and no snapshots are displayed in the list.

### versions

CloudStack 4.22.1.0 on Rocky Linux 10.
Ceph storage.

### The steps to reproduce the bug

1. I think the error was triggered forcing the deletion of a VM which had a volume snapshot
2. delete the volume snapshot of the deleted VM
3.
...

### What to do about it?

_No response_

未指定檔案或測試。首先按照列出的步驟，在使用 Ceph 的 CloudStack 4.22.1.0 上重現故障，然後從回報的 null VolumeVO 例外開始追蹤 Volume Snapshots 清單。完成的標準是清單能夠無錯誤載入，並處理其 VM 或 volume 已被刪除的快照。

由索引模型根據 Issue 內容生成。