fix(git): add vendor in .gitignore

vendor/golang.org/x/sys/cpu/cpu_wasm.go

@@ -1,18 +0,0 @@
-// Copyright 2019 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 wasm
-// +build wasm
-
-package cpu
-
-// We're compiling the cpu package for an unknown (software-abstracted) CPU.
-// Make CacheLinePad an empty struct and hope that the usual struct alignment
-// rules are good enough.
-
-const cacheLineSize = 0
-
-func initOptions() {}
-
-func archInit() {}