all: use any instead of interface{}

My favorite part of generics.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>

wgengine/router/router_windows.go

@@ -28,7 +28,7 @@ import (
 )
 
 type winRouter struct {
-	logf                func(fmt string, args ...interface{})
+	logf                func(fmt string, args ...any)
 	linkMon             *monitor.Mon // may be nil
 	nativeTun           *tun.NativeTun
 	routeChangeCallback *winipcfg.RouteChangeCallback