feat(netlink): detect IPv6 using query to address

- If a default IPv6 route is found, query the ip:port defined by `IPV6_CHECK_ADDRESS` to check for internet access

internal/cli/noopfirewall.go

@@ -0,0 +1,14 @@
+package cli
+
+import (
+	"context"
+	"net/netip"
+)
+
+type noopFirewall struct{}
+
+func (f *noopFirewall) AcceptOutput(_ context.Context, _, _ string, _ netip.Addr,
+	_ uint16, _ bool,
+) (err error) {
+	return nil
+}