flake/chv: bump cloud-hypervisor-src + adapt to new crate structure

Since PR #7525 (Dec 2025)[0], Cloud Hypervisor uses a virtual Cargo manifest and
the main package was moved to the `./cloud-hypervisor` subdirectory. This change
is effective since v50, which we just upgraded to [1].

[0] cloud-hypervisor/cloud-hypervisor#7525
[1] cyberus-technology/cloud-hypervisor#60

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com

Author: phip1611

chv.nix

@@ -16,6 +16,10 @@ let
 
   commonArgs =  {
       src = craneLib'.cleanCargoSource cloud-hypervisor-src;
+      # Since Nov 2025 (v50), Cloud Hypervisor has a virtual manifest and the
+      # main package was moved into a sub directory.
+      cargoToml = "${src}/cloud-hypervisor/Cargo.toml";
+
       meta = cloud-hypervisor-meta;
 
       # Pragmatic release profile with debug-ability and faster