feature(krata): first pass on cpu hotplug support (#340)

* fix(runtime): adjust memory resources inside a transaction

* feature(krata): first pass on cpu hotplug support

crates/xen/xenclient/examples/boot.rs

@@ -27,6 +27,7 @@ async fn main() -> Result<()> {
         base: BaseDomainConfig {
             uuid: Uuid::new_v4(),
             max_vcpus: 1,
+            target_vcpus: 1,
             max_mem_mb: 512,
             target_mem_mb: 512,
             enable_iommu: true,