Remove legacy code (#3838)

* Add feature migration notice

* Remove legacy code of transport processing

* Clear legacy proto field

* Fix missing

* Unify protocolname

* Test remove

* Supressor

* Weird code

* Remove errorgen related comments

proxy/wireguard/wireguard.go

@@ -12,8 +12,6 @@ import (
 	"golang.zx2c4.com/wireguard/device"
 )
 
-//go:generate go run github.com/xtls/xray-core/common/errors/errorgen
-
 var wgLogger = &device.Logger{
 	Verbosef: func(format string, args ...any) {
 		log.Record(&log.GeneralMessage{