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_

未指定文件或测试。首先按照列出的步骤，在使用 Ceph 的 CloudStack 4.22.1.0 上重现故障，然后从报告的 null VolumeVO 异常开始跟踪 Volume Snapshots 列表。完成的标准是列表能够无错误加载，并处理其 VM 或 volume 已被删除的快照。

由索引模型根据 Issue 内容生成。