network: remove `wasCachedInterfaceLoaded` from slirp binding
network: remove `wasCachedInterfaceLoaded` from slirp binding

Somehow this now unused method was left behind.

Signed-off-by: Miguel Duarte Barroso <c798d3f0e4fda7badfc3bbd91babde7ebd48b6c2@redhat.com>

stu-gott/kubevirt,stu-gott/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt,davidvossel/kubevirt,stu-gott/kubevirt,davidvossel/kubevirt,davidvossel/kubevirt,stu-gott/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt,davidvossel/kubevirt