Fix concurrent access issues with ConnectedClients

Replaced direct access to GameMain.Server.ConnectedClients with array snapshots in multiple server-side classes to prevent concurrent modification issues during parallel updates. Also updated PhysicsBody and LevelTrigger to avoid static/shared state in parallel contexts, improving thread safety and reliability.

Barotrauma/BarotraumaServer/ServerSource/Events/EventActions/StatusEffectAction.cs

@@ -25,4 +25,4 @@ namespace Barotrauma
             }
         }
     }
-}
+}