Blocks should be synchronized on read-only fields (#5212)

* Blocks should be synchronized on read-only fields

* more readonlys

* fix alignment

* more

* Update ISelfController.cs

* simplify new

* simplify new

src/Ryujinx.Audio/AudioManager.cs

@@ -11,7 +11,7 @@ namespace Ryujinx.Audio
         /// <summary>
         /// Lock used to control the waiters registration.
         /// </summary>
-        private object _lock = new object();
+        private readonly object _lock = new();
 
         /// <summary>
         /// Events signaled when the driver played audio buffers.