chore: Improve performance of NetworkList set operation

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -19,6 +19,8 @@ Additional documentation and release notes are available at [Multiplayer Documen
 
 ### Changed
 
+- Optimized `NetworkList<T>` indexer setter to skip operations when the new value equals the existing value, improving performance by avoiding unnecessary list events and network synchronization. (#3587)
+
 
 ## [2.5.0] - 2025-08-01
 

com.unity.netcode.gameobjects/Runtime/NetworkVariable/Collections/NetworkList.cs

@@ -617,6 +617,13 @@ public T this[int index]
                 }
 
                 var previousValue = m_List[index];
+
+                // Only trigger an event if the value has changed
+                if (NetworkVariableSerialization<T>.AreEqual(ref previousValue, ref value))
+                {
+                    return;
+                }
+
                 m_List[index] = value;
 
                 var listEvent = new NetworkListEvent<T>()