adjust test since other features were merged since

Author: ktoso

test/Distributed/distributed_actor_system_missing.swift

@@ -9,7 +9,11 @@ import _Distributed
 distributed actor DA {
   // expected-error@-1{{distributed actor 'DA' does not declare ActorSystem it can be used with.}}
 
-  // expected-note@-3{{you can provide a module-wide default actor system by declaring:}}
+  // Since synthesis would have failed due to the missing ActorSystem:
+  // expected-error@-4{{type 'DA' does not conform to protocol 'Encodable'}}
+  // expected-error@-5{{type 'DA' does not conform to protocol 'Decodable'}}
+
+  // expected-note@-7{{you can provide a module-wide default actor system by declaring:}}
 
   // Note to add the typealias is diagnosed on the protocol:
   // _Distributed.DistributedActor:3:20: note: diagnostic produced elsewhere: protocol requires nested type 'ActorSystem'; do you want to add it?