Fix missing vendor dir

vendor/github.com/tklauser/go-sysconf/sysconf_solaris.go

@@ -0,0 +1,14 @@
+// Copyright 2021 Tobias Klauser. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package sysconf
+
+import "golang.org/x/sys/unix"
+
+func sysconf(name int) (int64, error) {
+	if name < 0 {
+		return -1, errInvalid
+	}
+	return unix.Sysconf(name)
+}