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.

Bắt đầu với com.cloud.upgrade.SystemVmTemplateRegistration.registerOrUpdateSystemVmTemplate tại SystemVmTemplateRegistration.java:1040 và xem lại các log nâng cấp để tìm template HyperV bị thiếu trong /usr/share/cloudstack-management/templates/systemvm/. Tái hiện quá trình nâng cấp từ 4.20.1 lên 4.22 với các hypervisor được liệt kê, sau đó xác minh rằng các template SystemVM của 4.22 được đăng ký mà không gặp lỗi checksum hoặc Cannot upgrade system VMs.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.