fix: fix dns on linux (#336)

* fix: fix dns on linux

* feat: detect run in Github action or not to setup DNS

vendor/github.com/tailscale/netlink/route_unspecified.go

@@ -0,0 +1,21 @@
+// +build !linux
+
+package netlink
+
+import "strconv"
+
+func (r *Route) ListFlags() []string {
+	return []string{}
+}
+
+func (n *NexthopInfo) ListFlags() []string {
+	return []string{}
+}
+
+func (s Scope) String() string {
+	return "unknown"
+}
+
+func (p RouteProtocol) String() string {
+	return strconv.Itoa(int(p))
+}