Clean up libvirt network

Clean up libvirt network once the script has
finished successfully.

test/cases/ostree-ng.sh

@@ -331,6 +331,9 @@ clean_up () {
     sudo virsh undefine "${IMAGE_KEY}-uefi" --nvram
     # Remove qcow2 file.
     sudo rm -f "$LIBVIRT_UEFI_IMAGE_PATH"
+    # Clear integration network
+    sudo virsh net-destroy integration
+    sudo virsh net-undefine integration
 
     # Remove any status containers if exist
     sudo podman ps -a -q --format "{{.ID}}" | sudo xargs --no-run-if-empty podman rm -f