feature/relayserver,wgengine/magicsock: remove WIP gating of peer relay (#16533)

Updates tailscale/corp#30051

Signed-off-by: Jordan Whited <jordan@tailscale.com>

feature/relayserver/relayserver.go

@@ -14,7 +14,6 @@ import (
 	"sync"
 	"time"
 
-	"tailscale.com/envknob"
 	"tailscale.com/feature"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnext"
@@ -133,9 +132,6 @@ func (e *extension) relayServerOrInit() (relayServer, error) {
 	if e.hasNodeAttrDisableRelayServer {
 		return nil, errors.New("disable-relay-server node attribute is present")
 	}
-	if !envknob.UseWIPCode() {
-		return nil, errors.New("TAILSCALE_USE_WIP_CODE envvar is not set")
-	}
 	var err error
 	e.server, err = udprelay.NewServer(e.logf, *e.port, nil)
 	if err != nil {

wgengine/magicsock/magicsock.go

@@ -2724,8 +2724,7 @@ func (c *Conn) onNodeViewsUpdate(update NodeViewsUpdate) {
 
 	relayClientEnabled := update.SelfNode.Valid() &&
 		!update.SelfNode.HasCap(tailcfg.NodeAttrDisableRelayClient) &&
-		!update.SelfNode.HasCap(tailcfg.NodeAttrOnlyTCP443) &&
-		envknob.UseWIPCode()
+		!update.SelfNode.HasCap(tailcfg.NodeAttrOnlyTCP443)
 
 	c.mu.Lock()
 	relayClientChanged := c.relayClientEnabled != relayClientEnabled