vendor: Update everything

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4620

vendor/golang.org/x/net/ipv6/sys_stub.go

@@ -2,12 +2,12 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build nacl plan9
+// +build !darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd,!solaris,!windows
 
 package ipv6
 
 var (
 	ctlOpts = [ctlMax]ctlOpt{}
 
-	sockOpts = [ssoMax]sockOpt{}
+	sockOpts = map[int]*sockOpt{}
 )