fix(git): add vendor in .gitignore

vendor/github.com/gin-gonic/gin/internal/bytesconv/bytesconv.go

@@ -1,24 +0,0 @@
-// Copyright 2020 Gin Core Team. All rights reserved.
-// Use of this source code is governed by a MIT style
-// license that can be found in the LICENSE file.
-
-package bytesconv
-
-import (
-	"unsafe"
-)
-
-// StringToBytes converts string to byte slice without a memory allocation.
-func StringToBytes(s string) []byte {
-	return *(*[]byte)(unsafe.Pointer(
-		&struct {
-			string
-			Cap int
-		}{s, len(s)},
-	))
-}
-
-// BytesToString converts byte slice to string without a memory allocation.
-func BytesToString(b []byte) string {
-	return *(*string)(unsafe.Pointer(&b))
-}