Multipass fails to start VMs on Windows 10 after recent changes

[levkropp]

Describe the bug
A regression has been introduced in the full branch of Multipass that causes VMs to fail to start correctly on Windows 10 using Hyper-V. The system gets stuck on "starting VM" or "starting primary" without progressing. In the Event Viewer, Hyper-V errors appear indicating it cannot find the virtual machine with the name "primary". There also appear to be hangs on the "Waiting for SSH to be up" Event during VM startup occasionally, or after a long period of time

To Reproduce
Clone the full branch and build it.
Install Multipass on Windows 10.
Run the command multipass start to start a VM.
Observe that the VM fails to start, with the GUI getting stuck at "starting" and the Event Viewer logging the error:

Hyper-V was unable to find a virtual machine with name "primary".

Expected behavior
VMs should start successfully without any issues. multipass start and other commands should work as expected without hanging or errors related to Hyper-V. The "Waiting for SSH to be up" issue should not occur.

Logs
[primary] [14616] stderr: Get-VM : Hyper-V was unable to find a virtual machine with name "primary".
At line:1 char:1

Get-VM -Name primary

  + CategoryInfo          : InvalidArgument: (primary:String) [Get-VM], VirtualizationException
  + FullyQualifiedErrorId : InvalidParameter,Microsoft.HyperV.PowerShell.Commands.GetVM

Additional info
OS: Windows 10 Pro
CPU architecture: x86_64
Multipass Version: reproducible on full, change-permissions-on-instances, not reproducible on 1.15.0 or base-merge-full

Additional context
The PR where this bug was discovered: PR #668 - Change permissions on instances.

[levkropp]

Fixed by #3971