Ensure speech bubble cap is always respected (#32223)

Ensure speech bubble cap is respected, even when messages are sent very fast

Content.Client/UserInterface/Systems/Chat/ChatUIController.cs

@@ -467,8 +467,9 @@ public sealed class ChatUIController : UIController
 
         if (existing.Count > SpeechBubbleCap)
         {
-            // Get the oldest to start fading fast.
-            var last = existing[0];
+            // Get the next speech bubble to fade
+            // Any speech bubbles before it are already fading
+            var last = existing[^(SpeechBubbleCap + 1)];
             last.FadeNow();
         }
     }