Call verify_go_version at the END of setup_env

Prior to this it would download Go, setup the environment, then (maybe)
download Go again.

I renamed verify_go_version to be internal and fixed all callers.

hack/update-netparse-cve.sh

@@ -29,7 +29,6 @@ source "${KUBE_ROOT}/hack/lib/init.sh"
 source "${KUBE_ROOT}/hack/lib/util.sh"
 
 kube::golang::setup_env
-kube::golang::verify_go_version
 
 # Ensure that we find the binaries we build before anything else.
 export GOBIN="${KUBE_OUTPUT_BIN}"