fix(e2e): fix argument for az sig image-version create (#968)

It appears there's been a regression in version 2.59.0 of the Azure CLI,
where az sig image-version create fails when being passed the
--managed-image flag, see the related [failing CI
run](https://github.com/ubuntu/adsys/actions/runs/8677801641/job/23793927248
), and the [reported
issue](Azure/azure-cli#28700) on the azure-cli
project.

Because of this we are not able to create new versions for any of our VM
templates.

To fix this we can apply the workaround from the linked issue and pass
the VM ID inside the `--virtual-machine` argument. I've tested this
locally and successfully created a new image version with the change.

Partly fixes UDENG-2528

e2e/cmd/build_base_image/02_create_vm_template/main.go

@@ -116,7 +116,7 @@ func action(ctx context.Context, cmd *command.Command) error {
 		"--gallery-image-version", nextImageVersion,
 		"--target-regions", "westeurope", "eastus=1=standard_zrs",
 		"--replica-count", "2",
-		"--managed-image", inv.VMID,
+		"--virtual-machine", inv.VMID,
 		"--tags", "project=AD", "subproject=adsys-e2e-tests",
 	)
 	if err != nil {