fix(git): add vendor in .gitignore

vendor/golang.org/x/sys/windows/mksyscall.go

@@ -1,10 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build generate
-// +build generate
-
-package windows
-
-//go:generate go run golang.org/x/sys/windows/mkwinsyscall -output zsyscall_windows.go eventlog.go service.go syscall_windows.go security_windows.go