chore: stop using default mux in SDK server

This is essentially a hack. We need to be able to run the SDK server twice in
Obot to fix some short-term dependency cycles. We are unable to do this if both
use the default server mux. This change will use a separate mux for each.

Signed-off-by: Donnie Adams <donnie@obot.ai>

Author: thedadams

pkg/sdkserver/server.go

@@ -126,10 +126,11 @@ func run(ctx context.Context, listener net.Listener, opts Options) error {
 	}
 	defer s.close()
 
-	s.addRoutes(http.DefaultServeMux)
+	mux := http.NewServeMux()
+	s.addRoutes(mux)
 
 	httpServer := &http.Server{
-		Handler: apply(http.DefaultServeMux,
+		Handler: apply(mux,
 			contentType("application/json"),
 			addRequestID,
 			addLogger,