SystemVM template registration failure in upgrading to 4.22

### problem

When upgrading an environment on 4.20.1 with KVM,VMware and Xenserver hypervisors the upgrade process reported an error in upgrading HyperV SystemVM template.

Workaround : Download the template from https://download.cloudstack.org/systemvm/4.22/systemvmtemplate-4.22.0-x86_64-hyperv.vhd.zip to /usr/share/cloudstack-management/templates/systemvm/ on the management server before upgrade. Or use the old method to register the systemVM templates after restarting the service.

```
2025-11-14 05:55:59,844 DEBUG [c.c.u.SystemVmTemplateRegistration] (main:[]) (logid:) /usr/share/cloudstack-management/templates/systemvm/systemvmtemplate-4.22.0-x86_64-hyperv.vhd.zip is not present
2025-11-14 05:55:59,844 ERROR [o.a.c.u.s.DigestHelper] (main:[]) (logid:) Failed to calculate sha512 checksum of template
2025-11-14 05:55:59,847 ERROR [c.c.u.SystemVmTemplateRegistration] (main:[]) (logid:) Exception while registering/updating system VM templates for hypervisors in metadata com.cloud.utils.exception.CloudRuntimeException: Failed to register 4.22.0 templates for hypervisors: [vmware,xenserver,kvm-x86_64,hyperv]. Cannot upgrade system VMs
at com.cloud.upgrade.SystemVmTemplateRegistration.registerOrUpdateSystemVmTemplate(SystemVmTemplateRegistration.java:1040)
```

### versions

4.20.1

### The steps to reproduce the bug

Upgrade 4.20.1 to .422 with KVM,VMware and Xenserver

### What to do about it?

Something is wrong in the upgrade process, needs to be fixed. The issue was not seen when upgraded to RC versions of 4.22, only with KVM.

從 SystemVmTemplateRegistration.java:1040 的 com.cloud.upgrade.SystemVmTemplateRegistration.registerOrUpdateSystemVmTemplate 開始，檢查升級日誌中 /usr/share/cloudstack-management/templates/systemvm/ 下缺少的 HyperV 範本。使用列出的 hypervisor 重現從 4.20.1 到 4.22 的升級，然後確認 4.22 SystemVM 範本註冊時不會出現 checksum 或 Cannot upgrade system VMs 錯誤。

由索引模型根據 Issue 內容生成。