Update src/Hosting/TestHost/test/TestClientTests.cs

Co-authored-by: Copilot <[email protected]>

Author: BrennanConroy

src/Hosting/TestHost/test/TestClientTests.cs

@@ -825,8 +825,6 @@ public async Task WebSocketSubProtocolsWorks()
         await host.StartAsync();
 
         var server = host.GetTestServer();
-#pragma warning restore CS0618 // Type or member is obsolete
-
         // Act
         var client = server.CreateWebSocketClient();
         client.SubProtocols.Add("alpha");