add new files for compat layer

udp/wireguard_conn_unsupported.go

@@ -0,0 +1,15 @@
+//go:build !linux || android || e2e_testing
+
+package udp
+
+import (
+	"fmt"
+	"net/netip"
+
+	"github.com/sirupsen/logrus"
+)
+
+// NewWireguardListener is only available on Linux builds.
+func NewWireguardListener(*logrus.Logger, netip.Addr, int, bool, int) (Conn, error) {
+	return nil, fmt.Errorf("wireguard experimental UDP listener is only supported on Linux")
+}